(Oh, that's not what you had in mind?)
The simple fact of the matter is that denominations exist because we don't agree completely. The idea is that we are all Christians de nomine (of the name) __________.
Denominations certainly beat the heck out of trying to make all Christianity homogeneous in their theology. That's been tried before, and it resulted in horrors like the Inquisition.
What's wrong with homogenity of belief if it's the true belief? The question is......is your belief true is is mine? Or is neither?
True, but I would argue that this isn't a bad thing. There were various sects of Judaism during the days of Jesus and He never made a judgment on which one was the "right" one. Different denominations have different purposes -- Baptists are good at reading the Bible and evangelizing, Pentecostals are good at praise and worship, Greek Orthodox are good on the mystic aspects of Christianity, and Roman Catholics are good at Inquisitions (just kidding on that one, Black Elk!!!!!). I don't think that God cares too much about our denominations.