Blackcat,
I don't have very many answers but I'm going to commiserate with you. Our DD is younger than your DS but our extended families are extremely religious and DH and I don't share their beliefs. If they knew what we really thought on the topic they'd be organizing prayer chains for us.
Before we had children we struggled with what we were going to tell them about God/religion. We didn't feel right telling a small child that there was no God but we also didn't want to decree that the existence of God was unquestionable. We decided that we would tell the kids that God was a benevolent force that they could talk to if they felt scared and that the force would listen and that the act of talking would make them feel better. When DD asks us or says something regarding a religious belief to us, we respond by saying that is what some people believe. Sometimes when it's appropriate we ask her what she believes and we say great to what ever she answers. We've left the door open for her to develop her own beliefs or join a religion of her own choosing. That said, her questioning beliefs and having these type of discussions would not go over well at the Thanksgiving table. We've explained to her that there are some topics that we discuss at home freely but that other people may not feel comfortable with those topics. We tell her that everyone is entitled to their beliefs and we don't need to all agree. It's not always imperative that we let others know that we disagree with them either. So far this has kept us from having any explosive confrontations. Hopefully it continues to work.
