Everyone needs to begin explaining things about God to their children, and how to recognize and counter the lies they will have thrown at them, from a VERY early age. Kids need to learn, from a Christian worldview, about the common false things and lies they will otherwise learn and absorb at school from their smarty pants friends. They are best equipped if, from a young age, they know how to confidently respond to the basic untruths they will encounter, better helping them to think for themselves and be better resistant to peer pressure. Many foolishly wait until their kids are entering their teens or troublesome behavior before they get serious about teaching them about such things. OR, they just assume their kids will learn what they need to know at church or Sunday School, etc. But, by then - they'll likely, already have developed false beliefs and will also have learned how to hide them from you. The less they know, the more vulnerable they'll be. By the time most kids are 10, they already have encountered so many false things, that if they've not been taught how to understand them and the TRUTH of why they're wrong, then they'll remain increasingly vulnerable to the lies common to our culture!
Here are some wonderful and FUN resources for teaching young kids what they need to know about God and truth, and on THEIR levels of understanding: https://www.youtube.com/watch?v=Q1dj6j8yYAk