One reason I've never felt particularly in sync with other Christians is that my belief in God A) is logically prior to my belief in Christ, and B) my commitment to Christianity is based partly on willful commitment, alongside rational persuasion - with emotional investment taking the hindmost.
I never had a moment, as near as I can remember, where I suddenly had tears in my eyes at realizing the presence of a loving God who wanted a personal relationship with me and who really loved me. I'll go further - I find people for whom this kind of experience is key to their theism (or the lack of it, the key to their atheism) to be... pretty weird, frankly. I'm ill at ease around people whose emotions seem to drive their intellectual lives, rather than the reverse, even if I'm on the same page with them politically and religiously.
One problem with this is, there's very little social space for people with the attitude I have. There is no real group for people convinced by mere theism, and the belief in God or gods or designer, in and of itself, gets treated intellectual as at best a waypoint towards an ultimate religious destination. This, lack, I think, is one of the current and largest cultural mistakes, one that needs addressing. Intelligent Design came within a razor's edge of addressing it, but ultimately was sandbagged by a combination of a dishonest and vicious media treatment, as well as - to be frank - a substantial portion of their own membership treating the entire thing as a Christian project.
That means I've been pretty isolated for a long time when it comes to the question of God's existence, because - even if I'm Catholic, even if I'm pretty damn orthodox - I'm just approaching the whole question in a way that is utterly alien to most people, and I know it.
Luckily I'm a guy who prefers isolation to the usual alternatives.