If you notice, I said "we have such different ideas about the faith." By the term "the faith" I include the entire content of faith or belief, all those "differences in our ideas about worship, religious practice, and sacraments."
IMHO there isn't an animal named "the faith," it is "my" faith and "your" faith.
Coming from my background, I can actually see our commonalities much better than I see our differences....I guess it's all a matter of perspective (not ours, but His)
There IS unitiy in the Christian faith....we just need to open our eyes and accept it.