We all have to bring up our children with a set of beliefs about how the world us functions, about how to act, about the nature of reality. We have to do that because children ask about it. Who am I? Who would I be if I wasn't me? What happens to the guinea pig when it dies? Where was I before I was in mummy's tummy? Why can't I do what I like? -- and many more. These are metaphysical questions, that is they're not like 'what is the earth made of' or 'how did mummy and daddy make me'. They can't be answered without drawing on our underlying philosophical and religious beliefs.
Atheists and Christians (for example) might well answer these questions in different ways. But atheists will still have to draw on a stock of underlying beliefs to answer them - perhaps they might say that the guinea pig goes to sleep and never wakes up, or that before you were conceived you didn't exist, or that if you were someone else you could never know what that was like, or that you can't do what you like because you have to do what is best for everybody. Or you might give other answers. Whatever you might say, they would be metaphysical statements, that is relating to non-materially based ideas. And atheists have those just as much as Christians or any other people of faith. That's why some people say (mistakenly) that atheism is a belief system. It's not, but that doesn't mean that atheists don't have beliefs about the nature of reality, or ethics, or life after death etc that underpin their atheism.
By the same token, because children do ask those questions, and because we need to answer them, we inevitably pass on our beliefs to our children. And we have to. We can't, for example, allow them to grow up without any ethical principles because they need to work them out for themselves when they grow up. Actually we have to teach them not to hurt other people, not to lie, not to grab what other people have, and so on, right now.
It's the same with our metaphysical beliefs. We do and must pass them on to our children, not least because children want to know about them now. And, of course, we bring our children up in the culture of our family. We teach them that they are unique and special by celebrating their birthday, for example, and we pass on all kinds of underlying attitudes by what we do both on special occasions and everyday. We can't bring them up as blank slates (and actually, what would a blank slate child be like? perhaps like one of those children who have never learned language and been brought up outside human society - those children are irreparably damaged).
So I have brought my children up answering their questions in terms of my own Christian faith, and I have taken them to church and prayed with them because those are important activities for my family. Of course, I'd love it if as adults they decided to make Christianity central to their lives - in my view the Christian faith adds depth and richness and beauty to our lives and allows us to live more fully. But I can only invite them to do this, I can't make them. I can't make them have faith because that is a matter for them. All I can do is to show them what having a faith is like and teach them about it. They will get exposure to other ways of living, and other beliefs in their lives - they know lots of atheists in our wider family, let alone in their friendship groups and wider society. And that's fine.