* * *
I think the social aspect of Christianity is extremely important. I agree wholeheartedly with you on that. I would quibble, however, with the seeming dichotomy you make between this important social, communal aspect and dogma.
One can never ultimately decide (and least not sensibly, in my opinion) on which church or faith to embrace without analyzing or comparing very carefully the doctrines involved. After all, we all say a creed every Sunday, don't we? That is part of the communitarian aspect of Christianity: we join together in unity and say the creed, which is precisely what binds us together in the first place.
Now, love is also supreme in the priorities of a Christian, and in community. Rather than squabble over whether Orthodoxy or Catholicism "does" community and the social thing better, why can't we all get together in the sense of ecumenical unity, as much as possible?
By that I don't mean the liberal ersatz "ecumenism" of pretending there are no differences when there clearly are, but to treat each other with love and respect, and rejoice in what we do have in common. We can hardly talk about Christian community and treat each other the way we so often do. After all, we are all Christians, and that should make a major difference in how we approach each other, no?
C.S. Lewis's exposition of "mere Christianity" is sometimes misunderstood, to mean a sort of "lowest common denominator" unity which doesn't amount to much. But if you read closely, Lewis said that we all had the great "hall" in common, where we could meet on the grounds of all the similarities. He also said, however, that everyone also has his own "room" (his particular church or belief-system) that he goes back to at night.
Simply emphasizing the profoundly social nature of Christianity does not resolve the problem of how dogma fits into that. All trinitarian Christians would agree, it seems to me, about the following scenario:
A) A Mormon congregation which offers superb social support, caring among the flock, excellent financial and pastoral aid, etc.In which one would or should we choose to worship? It's no contest: one cannot worship in a place where they do not accept the doctrines being taught, no matter how great the "fellowship" is.
B) An Orthodox or Catholic congregation (take your pick) which teaches true doctrine, but unfortunately does a lousy job at the social, familial, emotional support, fellowship level.
Of course, we all want to find a church where both things are present. Yes, we do, but human beings being what they are (fallen, sinners), this is rarely achieved. God has seen to it (I believe) that doctrine has been preserved, but He has not promised that going to church or being a member of a local church will be some kind of utopia. The "sin argument" never proves that one brand of Christianity is true and another false. That must be a doctrinal determination.
If a particular congregation is doing a lousy job in the non-doctrinal aspects of Christianity, then each of us who hypothetically wanted to possibly join it could either: 1) join in as yet another sinning hypocrite, or 2) try to show a better way, and help "reform" it, if by God's grace we feel we can offer the group something positive.
You asked, "What are your experiences?" Mine have been precisely what I described above: I've never found this wonderful, perfect Church or church (local congregation) that got all this right. But in every church I have attended, I have been able to ascertain whether I agree with their doctrinal stance.
When I attended the Assemblies of God I disagreed with one point of their doctrinal formulation: the one which held that everyone should speak in tongues to be properly filled with the power of the Holy Spirit. I never believed that, so I simply didn't become a member, in good conscience. The matter never came up, but I was true to myself and my conscience.
I haven't found any Catholic congregation to be anything nearly what I would like for it to be, but at the end of the day, my social relationships are not confined to my local congregation. I can fulfill that personal need and sense of community with friends from a much larger network, including Protestant and Orthodox and groups like home schooling networks, pro-life groups, (in my case) apologetic associations, etc. Why must all that be found in my local congregation (if it were, we'd be in rough shape)?
Sin and failure on this personal / social level will always be present, I guarantee that. If we find a wonderfully "socially-minded" congregation, great, but if we don't (which is the usual case), then we must accept that as the pervasive influence of sin that we can never avoid, anywhere we are.