Hey Marc, welcome to the Atheist Republic.
Well, I’m not married or with kids but I do live in a country, society and family full of religious people. My circumstances were such that the pain that religion caused me was evident for years, in both physical and mental form. I was going to psychologists and therapists, psychiatric hospitals and whatnot.
The point is, I had to announce that I’m outta this shit when I was on the brink of suicide. So, everyone in my family knows this about me.
I don’t think pulling out should cause major damage to your life and the people you love (for example, in a Muslim marriage, if either spouse changes their religion, the marriage is nullified). You’re changing your beliefs, not theirs. Unless I’m wrong, and you mean more extreme by “pulling out”
Having a religious wife is not a problem as long as she knows, understands and respects your lack of belief. Have you tried to talking to her? As for your kids and grandkids, once again, I don’t think you should talk to them at all, unless they all live with you. I’m assuming your wife is the one who’s with you all the time so she’s the one to whom you should reveal your doubts first.
The best way to approach a family member about your lack of beliefs or doubts thereof is to NOT attack their beliefs, but rather take the neutral approach and become the questioner.
For example, “how do you know there’s evidence for god” instead of “you’re wrong, there’s no evidence for god”. Since I’m young (21), I didn’t try to change anyone in my family. They all know I’m an atheist and we respect each other now, but mostly I have to tolerate a lot of religious advice and stuff from them. But, so what? I ignore it. It doesn’t harm me, I don’t even believe in it.
On religious festivals, I have to sometimes perform along with the other people of my religion, not because I believe in it, but because I don’t wanna make my family feel like I’ve ditched them or something. I’ve adapted to them, instead of trying to make them adapt to me. I’m an ex-Muslim, by the way.