In the comments section of this post, I've been having a debate with a Roman Catholic about this whole Protestantism thing, so perhaps now is a good time to write a post about the unity of the Church.
I. My Own Testimony
I suppose I may as well start by discussing my personal history. I grew up in the Church of the Nazarene (a Wesleyan denomination) but at various stages of my life I have regularly attended services with the Free Methodists (7 years), Baptists (3 years) and Lutherans (1 year), not counting smaller visits. I also like stepping into Anglican services, and even Catholic Masses (though out of respect for their rules I do not take communion with the Catholics).
While it's true I'm the sort of Protestant who reads the Catholic Encyclopedia for fun, my adventures in ecumenism (interactions between different branches of Christianity) really started in earnest at St. John's College. During my last semester there I attended Holy Trinity, a wonderful Antiochian Orthodox congregation in Santa Fe. When I had first been invited to visit the church my freshman year, it seemed like a bizarre eastern cult that just happened to also be about Jesus, but over time I came to realize the commonalities and differences more clearly. It had a profound effect on my spiritual and musical sensibilities. Also, the priest (St. John Bethancourt) is the most visibly holy person I have ever met on this earth. He cannot enter a room without caring about whatever person he meets within. I am eternally grateful for the treasures obtained during this time, yet after careful consideration of the differences in theology, I remain a Protestant.
As a graduate student I attended Layhill Community Church, where during the time for prayer any person could go up to the altar railing to pray with St. Wil, the associate pastor. He was a man of great faith and I noticed that eerie coincidences would sometimes occur after I prayed with him for things. (This is the kind of thing skeptics attribute to confirmation bias, but Christians attribute to Divine Providence.)
For instance, one Sunday I asked to be able to worship God better, and the following Tuesday, while opening a bottle of olive oil to cook with, I suddenly remembered all the passages in Scripture about anointing with oil and the Holy Spirit, and was full of joy and praise. Only afterwards did I remember what I had asked for. (Despite the potent significance of olive oil as an ingredient in several of the Catholic sacraments, the next example will be even more relevant for church unity.)
Another time I was praying at the altar with St. Wil for the unity of the church, and in the following week (or two at the most) my housemate St. Ray invited me to attend a new bible study for grad students at the Catholic Student Center just off the U Maryland campus! So of course I went, and actually attended for 4 years which was longer than he did. Each year the study was led by a different monk from the Dominican House of Studies in Washington DC (except one year we got a seminarian instead).
After Ray invited me, he suddenly got worried it would be disruptive if I started arguing with everyone about Protestantism, so I agreed to keep it cool. The first meeting I was silent about that, but vocal about everything else. The second meeting I confessed; they were rather surprised because they had thought I had been speaking in a particularly Catholic way about the allegorical meaning of Adam and Eve during the first meeting. I was even invited (along with the others) to sometimes lead class discussions, which I tried to do with a minimum of controversy, focusing on commonalities except when absolutely necessary.
I got to see a lot of their struggles with various aspects of Catholicism, and sometimes tried to formulate ways of looking at the problems which combines the strengths of both types of theology, e.g. "Sacraments are not a way that we manipulate God, they are a way that God manipulates us!" They were aware that I disagreed about certain important things, but even though we weren't in communion, there was still community and communication! It was excellent practice for charitable discussion, and I am deeply grateful that they were Catholic enough (the word Catholic means "universal", after all) to include me.
As I said, I tried to avoid excessive controversy in the group, but after hours I had some vibrant discussions with the Dominican brothers about Catholicism, and when I visited the House of Studies I got to have a friendly intellectual brawl, of the sort that causes so much consternation among people who don't like arguments, since they associate them with hostility. They gave me books by St. Cardinal Newman, whose epistemology ("theory of knowledge") I find a bit whacko, for the reasons mentioned in that recent comments section, the one in which I flagrantly violated Socrates' rule for good conversations. To keep things shorter, St. Bayes or bust!
II. An Index of Communion
As is well known, Jesus prayed for the unity of the Church, on the night of his betrayal:
My prayer is not for them alone. I pray also for those who will believe in me through their message, that all of them may be one, Father, just as you are in me and I am in you. May they also be in us so that the world may believe that you have sent me. I have given them the glory that you gave me, that they may be one as we are one—I in them and you in me—so that they may be brought to complete unity. Then the world will know that you sent me and have loved them even as you have loved me. (John 17:20-23)
for the unity of our love is one of the signs by which the world can see that our faith is real, thus fulfilling his command to us:
A new command I give you: Love one another. As I have loved you, so you must love one another. By this everyone will know that you are my disciples, if you love one another.” (John 13:34-35)
But unity is not easy. Although in a sense we Christians are already one due to being part of the body of Christ and "members of each other" (Romans 12:5), and in this way we are part of the One Holy Universal and Apostolic Church and the communion of the saints, practically speaking the expression of that unity may be impaired. Just as quarreling siblings may be one family genetically but not be united in affection, or quarrelling spouses may be one in flesh but divided in spirit.
So the expression of unity is something that requires us to all work together to exercise maturity of character, using the gifts which God has provided us. As St. Paul says:
But to each one of us grace has been given as Christ apportioned it. This is why it says:
“When he ascended on high,
he took many captives
and gave gifts to his people.” (Psalm 68:18)
(What does “he ascended” mean except that he also descended to the lower, earthly regions? He who descended is the very one who ascended higher than all the heavens, in order to fill the whole universe.) So Christ himself gave the apostles, the prophets, the evangelists, the pastors and teachers, to equip his people for works of service, so that the body of Christ may be built up until we all reach unity in the faith and in the knowledge of the Son of God and become mature, attaining to the whole measure of the fullness of Christ.
Then we will no longer be infants, tossed back and forth by the waves, and blown here and there by every wind of teaching and by the cunning and craftiness of people in their deceitful scheming. Instead, speaking the truth in love, we will grow to become in every respect the mature body of him who is the head, that is, Christ. From him the whole body, joined and held together by every supporting ligament, grows and builds itself up in love, as each part does its work. (Eph. 4:1-16)
So, how are we doing on this front?
Well, the bad news is that the Church has splintered into numerous different denominations, not all of which regard each other as being really Christian. And a few of them aren't really Christian, though most accept the basic truths of the faith as expressed in e.g. the Nicene Creed. But as St. Lewis pointed out a while back, the commonalities are far more profound than the differences.
Let's try to be honest about how bad this problem really is. The most common figure one hears (from atheists complaining about the fractiousness of Christians, Catholics complaining about the fractiousness of Protestants, or Protestants complaining about the fractiousness of everyone), is to simply count the number of denominations, getting some huge figure in the tens of thousands, but this is an absolutely terrible way to assess the state of Church unity!
First of all, a lot of these organizational splits were for historical reasons (based on how different groups got evangelized, or because of doctrinal differences or attitude towards slavery or something like that which is no longer a live issue) or were for administrative convenience (e.g. to deal with being in different countries, or because the churches have somewhat different organizational structures which would be difficult to combine), and are perfectly compatible with both groups thinking the other is really Christian and cooperating for the sake of God's kingdom.
It would be better to ask "What is the probability that two randomly selected devout Christians are in communion with each other?" This gives a numerical measure, a "communion index", describing the degree of church unity. The answer turns out to be about 1/3 (see below). Could be better, could be a lot worse.
Merely having administratively independent units is not the same thing as being divided in love, or in communion. Even the Catholics have 24 nearly-independent administrative units (which appoint their own leaders and have their own customs and rules, but remain in communion with the Pope and accept his doctrinal decrees), while the Eastern Orthodox have about 15 "autocephalous" (self-governing) churches. These two churches were in communion with each other until about 1054 when both sides started excommunicating each other over an arcane theological dispute. These excommunications were lifted in 1965, but the churches are still not in communion for other reasons.
There are also 6 independent Oriental Orthodox churches, a group of churches including e.g. the Copts who did not accept the decision of the Council of Chalcedon. Although I personally think Chalcedon provided the best language for understanding the Incarnation, in retrospect the "Monophysite" or "Miaphysite" group was probably just using different words to refer to the same thing, and were not really heretics in the same way that the Gnostics or Arians were. Thus it was wrong to excommunicate them; and this is not only my own opinion but also the opinion of the leaders on both sides:
Hence we wish to reaffirm solemnly our profession of common faith in the Incarnation of our Lord Jesus Christ, as Pope Paul VI and Patriarch Moran Mor Ignatius Jacoub III did in 1971: They denied that there was any difference in the faith they confessed in the mystery of the Word of God made flesh and become truly man. In our turn we confess that He became incarnate for us, taking to himself a real body with a rational soul. He shared our humanity in all things except sin. We confess that our Lord and our God, our Saviour and the King of all, Jesus Christ, is perfect God as to His divinity and perfect man as to His humanity. In Him His divinity is united to His humanity. This Union is real, perfect, without blending or mingling, without confusion, without alteration, without division, without the least separation. He who is God eternal and indivisible, became visible in the flesh and took the form of servant. In him are united, in a real, perfect indivisible and inseparable way, divinity and humanity, and in him all their properties are present and active.
The subtext here is the thing which only really mature people are capable of saying, namely: "Oops, I'm sorry, we were wrong." (However, since this original schism, the Catholic church has developed their theology further, so the churches are unfortunately still not in communion.)
Protestants have a lot more sects, but then again most Protestants regard most other Protestant groups as being really Christians, and therefore part of the Universal Church founded by Jesus. Nowadays the biggest disputes tend to be about the axis that runs from liberal/modernist to fundamentalist/literalist, rather than denominational loyalties. (I'm somewhere in the middle, since I think miracles have really happened and the Scriptures' teachings on e.g. sexual ethics and so on need to be taken seriously, but I also accept the findings of biology and physics and don't think rigid definitions of inerrancy are the right way to talk about the authority of the Scriptures.)
With a few exceptions, most Protestant denominations allow all those who confess Jesus as their Savior and Lord to take communion in their church. So does the Assyrian Church of the East, an ancient apostolic church which was at one time known as the Nestorian church because the heretic Nestorius was received there, but it is now generally regarded as unfair to tarnish the whole group by his opinions. (The Assyrian church is much smaller than the others, although historically it was very important and and even spread to China).
So for purposes of calculating the odds that two Christians will be in communion, Nicene Christianity is really divided into 4 large subgroups: 1) Catholics, 2) most Protestants, 3) Eastern Orthodox, and 4) Oriental (listed in decreasing order by number of adherents) plus some smaller groups. Because the groups are not all the same size, the coefficient is closer to 1/3 than 1/4.
III. Three Kinds of Unity
Is the reconciliation of the major branches of Christianity even possible? And what can we do to make a difference?
Catholics care the most about unity, and are willing to do the most in terms of practical accommodations. Also, although they are a big institution which changes very slowly, they do change, and they know how to fall in line behind the decisions of the Pope. The difficulty is that they think that their past official pronouncements are infallible, and that it is necessary to believe every one of them to be in communion with them. So in doctrinal terms, it is impossible for them to ever compromise. That sounds a lot like a deal breaker to me. Of course, if the Catholics are right about everything, then the hundreds of Protestant denominations would just need to all recognize this fact simultaneously. Right, that sounds plausible.
The Eastern Orthodox church is a lot closer in its theology to the Catholics, and it would be more feasible for them to hash out a compromise. And I will wildly celebrate any such union should it occur. But there's also a lot of bad blood between them as a result of various historical incidents (such as the Sack of Constantinople in 1204, which apparently some of the Orthodox remember as if it were yesterday). Plus the Catholics made political attempts to take over various of the Eastern patriarchies, which succeeded in creating a bunch of Eastern Rite Catholics, but alienated them further. Twice the two churches got a bunch of leaders together and announced they were reconciled, but both times the Eastern Orthodox back home refused to accept the decision.
So there's been so much entrenchment of the various sides, with enough bad history between Catholics/Protestants and Catholics/Orthodox etc. that the groups reuniting with each other seems to be quite impossible.
And it is impossible. Impossible for human beings, that is. Not impossible for God:
Jesus looked at them and said, “With man this is impossible, but not with God; all things are possible with God.” (Mark 10:27)
“‘If you can?” said Jesus. “Everything is possible for one who believes.” (Mark 9:23)
There's always the option of fasting and praying, and genuinely asking God to shine light into our hearts. Surely God is willing to act when the time is right:
If my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then I will hear from heaven, and I will forgive their sin and will heal their land. (2 Chronicles 7:14)
So the first step is to realize that it is something that God will do, not something we can do. All of the parties to this dispute believe that there is a God in heaven who can act, so why do we so frequently act as though a negative outcome were inevitable?
The second thing is to recognize how far we've come already. For a couple centuries, Protestants and Catholics were killing each other in order to try to come out ahead politically. Until everyone got sick of that and decided to have an Enlightenment with secular republics instead. The killings don't happen anymore, leaving aside Northern Ireland anyway.
Even after that, until quite recently (perhaps a century ago), many Catholics and Protestants seem to have believed that more or less everyone on the other side was going straight to Hell when they died. This era too has passed.
And it wasn't my generation's doing, either. It was the hard work of a few individuals in previous generations, who insisted on talking to each other and opening up honest communication, even when it seemed impossible. Vatican II was a pretty big deal too, what with Catholics rethinking their attitude towards Protestants and accepting some Protestant ideas in the process (e.g. Mass in the language of the people). Meanwhile, even if there are still some fundamentalists out there who think ecumenical dialogue is of the devil, for the most part Protestants also became more open to the idea that some Catholics have actual spirituality and relationships with Jesus, and that we can be allies in some ways.
“Thus the saying ‘One sows and another reaps’ is true. I sent you to reap what you have not worked for. Others have done the hard work, and you have reaped the benefits of their labor.” (John 4:37-38)
In fact the wounds of division have already begun to be healed. The first step was unity of love. This step came about when different Christian groups became genuinely interested in the well-being of Christians in the other groups (even before they convert to our side).
It is just barely possible to love a group of people and also think that they are lying scoundrels who will go straight to Hell, but we all know that love isn't what usually motivates this attitude. It's not a coincidence that the word "charity" is used to mean both "Love in the Christian sense" and also "Not interpreting what other people say in the worst possible light". When you care about people, you don't just want to see the negatives but also the positives. As St. Lewis writes in Mere Christianity:
Suppose one reads a story of filthy atrocities in the paper. Then suppose that something turns up suggesting that the story might not be quite true, or not quite so bad as it was made out. Is one's first feeling, 'Thank God, even they aren't quite so bad as that,' or is it a feeling of disappointment, and even a determination to cling to the first story for the sheer pleasure of thinking your enemies are as bad as possible? If it is the second then it is, I am afraid, the first step in a process which, if followed to the end, will make us into devils. You see, one is beginning to wish that black was a little blacker. If we give that wish its head, later on we shall wish to see grey as black, and then to see white itself as black. Finally we shall insist on seeing everything—God and our friends and ourselves included—as bad, and not be able to stop doing it: we shall be fixed for ever in a universe of pure hatred.
Compare to this attitude:
Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, always perseveres. Love never fails. (1 Cor 13:4-8)
There are always going to be silly, superficial reasons to condemn the other side. (No matter how many good arguments there are for a position, there will always also be some terrible ones!) But love does not look for reasons to condemn, but for reasons to rejoice. If it criticizes, it does so not to boost its own ego, but out of genuine caring and out of respect for the good it sees is already present. It is willing to investigate carefully before deciding that the other side are evil rebels.
The next stage is the unity of hope. This step comes when people not only care for those on the other side, but also actually believe that their situation isn't hopeless, that if we form friendships and have dialogues and do good for each other, then it may actually make a difference. This is the stage we are currently working at, in my opinion, although obviously one could always use more love to fuel the process.
With hope, we actually begin to desire to be in communion with each other, because we have begun to think it might one day be possible. And even now, we can want this together (making due allowances for the fact that what complete unity would look like, is itself one of the theological controversies in question), and we can pray for it together.
“Again, I assure you: If two of you on earth agree about any matter that you pray for, it will be done for you by My Father in heaven. For where two or three are gathered together in My name, I am there among them” (Matthew 18:19-20).
I'm thinking this means, two or three Christians who have to work a bit to understand each other and agree about something! (Not 2 or 3 self-satisfied Christians who are already primed to think in exactly the same way, and who don't care what anyone outside their group thinks.) Real unity requires effort, but the reward is that it produces real community:
How good and pleasant it is
when brothers live together in harmony!
It is like fine oil on the head,
running down on the beard,
running down Aaron’s beard
onto his robes.
It is like the dew of Hermon
falling on the mountains of Zion.
For there the Lord has appointed the blessing—
life forevermore. (Psalm 133)
Of course not all of us are called to ecumenical work trying to understand other types of Christians—some of us are to focus on serving individual congregations (which can already present enough challenges for reconciliation!), or to provide aid to non-Christians, or to evangelize, or to serve the body of Christ in some other way. We all belong to each other, and according to the law of our King, the Son of David:
The share of the man who stayed with the supplies is to be the same as that of him who went down to the battle. All will share alike. (1 Sam 30:24)
And the final stage will be the unity of faith, when the love that is between us is enough that God can work through it so that we fully recognize and repent of the divisions that are between us. I don't know exactly what a practical version of this would look like (and as I said, this is one of the very things which is disputed), but I can still work towards it. Jesus prayed for it; it is possible. Let's have it happen in this world rather than wait for the next one.
Speaking as a Protestant I would emphasize that this unity of faith does not necessarily require us to agree on the exact same list of doctrines. When St. Paul writes:
May the God who gives endurance and encouragement give you the same attitude of mind toward each other that Christ Jesus had, so that with one mind and one voice you may glorify the God and Father of our Lord Jesus Christ. Accept one another, then, just as Christ accepted you, in order to bring praise to God.
it is clear that for him, "one mind" does not actually mean "agrees about everything", for the theme of the entire previous chapter and a half up to this point (Romans 14:1-15:7) is about dealing with the situation in which two Christians disagree about disputable matters.
A doctrine can be true, or even important, without being an essential dogma which must be believed to be a real Christian. (Even Catholics don't think everything is a dogma, but they do have a procedure for moving more and more things into the "dogma" category... thus making reunion harder and harder as time passes.)
There's a terrible idea called "secondary separation" in a few Protestant circles, which is that you should not only separate yourself from Christians who disbelieve in the doctrines you think are essential, you should also separate from Christians who fail to separate from such people... and so on ad nauseum. Clearly, in the absence of a Pope, that can only end with a tiny schismatic group of self-righteous Pharisees. Which is why we shouldn't think that way!
Instead, we need to accept one another. This doesn't mean we shouldn't have any standards for what we mean when we call somebody else a Christian, since both Jesus (Matt 18:15-20) and St. Paul (1 Cor 5) taught that in extreme circumstances, the church can and should excommunicate people. But it does mean that our standards for other people need to be less strict than our standards for ourselves. To summarize in a picture:
Note what happens here if we allow the little circles to expand until they become as large as the big circles. In that case, we will come out of communion, by refusing to accept somebody else unless they are exactly like us. This is schism, in which a failure of love leads to a rupture in the bonds of faith.
Although I wrote "believe" in this picture, the same thing applies when we talk about which behaviors are acceptable in a Christian community. Here it is even easier, since we have more control over our behaviors than over our beliefs. To have a functioning community, we need to be strict with ourselves, but more accepting when it comes to the conduct of others.
People are always alert to hypocrisy, situations where somebody says that X is required but doesn't do X themselves. You might think of this as a situation where the "small" circle is actually bigger than the "big" circle, and the person is condemned by their own standards. But merely avoiding hypocrisy is not nearly enough. If two people each allow themselves to do everything they personally think is OK, then unless they have identical beliefs, one will step outside the bounds set by the other.
“Do not judge, and you will not be judged. Do not condemn, and you will not be condemned. Forgive, and you will be forgiven. Give, and it will be given to you. A good measure, pressed down, shaken together and running over, will be poured into your lap. For with the measure you use, it will be measured to you.” (Luke 6:37-38)
IV. How to get other Christians to accept you
It's fun to argue, and it may cause some individuals to move from one viewpoint to another, but I don't think it's where the most important work lies. If you want to contribute to church unity, the way to do it is to serve. The way to get other groups of Christians to recognize what you believe in, is not to fight them but to make yourself indispensable to them.
Think about St. Lewis' writings. He led millions to Christ, and to a deeper spirituality. He chose to write primarily about those things which Christians have in common. And the funny thing is, Christians of pretty much every kind all have him as their hero. For example, the Eastern Orthodox have a tendency to think that Orthodoxy is the One True Church, and many of them think that those outside of it aren't real Christians. And yet an enormous number of them admire and respect St. Lewis, an Anglican. Doesn't matter if it's inconsistent with their general views about the non-Orthodox, they're forced to recognize him as a Christian, because he is just too darn useful to their spiritual lives to anathematize.
“When Christ ascended on high,
he took many captives
and gave gifts to his people.”
The communion of saints operates through the gifts we give to each other. It has not been held back by denominational barriers. I have heard hymns written by Protestants sung in Catholic Masses; I have seen books written by Catholic saints provide guidance for Protestants. We are already one family, we just need to realize it.
So go and serve other groups of Christians. Find out what they need, and then give it to them. Make it so they can't help but see that the Spirit of God is moving you. (We are all quite willing to believe that the people who help our team are inspired from above.) At the very least, we are always able to pray for each other. Make the Lord's priorities your priorities:
When Jesus had washed their feet and put on His robe, He reclined again and said to them, “Do you know what I have done for you? You call Me Teacher and Lord. This is well said, for I am. So if I, your Lord and Teacher, have washed your feet, you also ought to wash one another’s feet. For I have given you an example that you also should do just as I have done for you. I assure you: A slave is not greater than his master, and a messenger is not greater than the one who sent him. If you know these things, you are blessed if you do them.” (John 13:12-17)