you should share your memories of your nephew with your children, they will ask questions and will want to know.
as far as religion, everyone is different in their beliefs. my hubby and i were both raised southern baptist, the difference being that i was taken to church adn learned things, but was allowed to draw my own conclusions, and it was stuffed down his throat. we have taken our kids to church most of their lives, and they are very familiar with our religion, but as they have grown and been exposed to outside influences we have not been a barrier to their exploration and seeking their own way. they all seem to be coming to their own conclusions which while not exactly what we were raised with it works for them. anything you try to force on children will eventually push them into rebellion, IMO.
lost