I think not knowing just what to believe is more disconcerting when you have children. I have twin daughters who are almost six and a son who is 19 mo. and I feel an obligation to show them the "right" path, but I'm just not sure what that path is.
My in-laws talk to them about Jesus a lot when they spend time with them and then later ask me if Jesus is making the rain or if Jesus was watching over them in Heaven before they were born. I don't know how to answer these types of questions. I love and respect my in-laws, but I know they would be very concerned if they knew that I just don't belief all that they do. My MIL is already worried about my son because he hasn't been baptized. She doesn't want his little soul to go to Limbo if anything should happen to him!
Sorry you have in-law problems like that. My in-laws seemed to either be unaware of, or ignore the fact that we never had our son baptized. And my folks had no problem with it!
I figure, IF a deity exists, it would be a mean, petty, and cruel one to penalize people for things that are not their fault. And if he/she/it created all people -- then we would have been created to doubt, to THINK. Just as I wouldn't admire some human who exhibited such nasty traits, I wouldn't worship some being who exhibited them.
I have raised my son (now 16) to respect other's beliefs, to make his corner of the world a better place, to be kind -- basically, the values that the extremists tend to think they have a lock on, but don't.
If you give your kids a sense of respecting others and themselves, I don't think you can go too far wrong!