One of these friends asked me what do you do with those questions? I think she's wanting to know how to get past the questions and to a place of confident belief once again.
How do I know?
I was one of those kids. Had all the answers. No time or tolerance for questions or seeking. But at some point, when my examples didn't lead me to God any more (in fact, the opposite may have been true), and when the answers didn't bring me closer to God, I had to discover these things for myself.
The path for each of us is different. The experiences we have that raise the questions vary.
But I believe if we never get to the stage of wondering and evaluating and trying to find answers outside the Sunday school class, we are in danger of never really owning our faith and thus not having the type of personal, intimate relationship with God that He created us for. And I mean that in both senses--He created us so He could have a relationship with us as much as He created us to have a relationship with Him.