Well, I can share that we've been attending a congregational style church here in New England- so kind of more formal but similar to our old Presbyterian church. It's been very interesting bringing our not-yet-tested-but-probably-gifted child to the 'children's moment' portion of church.
The kids are supposed to sit on the stairs and have a nice informal chat with the pastor/speaker for that morning- usually a simple, easily understood lesson with a visual demonstration/aid of some sort.

Well, by age 2 my DS was LOUDLY incessantly insistently asking questions during the children's moment.
"Where IS God? Is he in the belltower? Is God in THIS PLACE? Can we see him now? I'd like to see Jesus, please"
You get the picture. Imagine all the parishioners uncomfortably shifting in their pews when my child is asking if God is in this place. Yikes.

I guess my point is, we've kept a sense of humor, we've done the best to meet him where he was conceptually and developmentally. Also, I don't have the answers, none of us can explain it all, and besides, we'd disagree. So, I ponder, describe things the way I feel are most helpful to MY child while honoring my version of religion, and use the 'faith' card. I don't know why/how, but that is what I have put my faith in...