Editor’s note: On tonight’s NewsHour, author Wendy Thomas Russell will talk to the NewsHour’s Jeff Brown about her book, “Relax, It’s Just God: How and Why to Talk to Your Kids About Religion When You’re Not Religious.” Read an excerpt of the book below.

Lots of secular parents think religion is too complicated for young children to comprehend, and some worry that early exposure to religious ideas will bias children in one way or another. But waiting is a gamble. Kids are capable of so much more than we give them credit for. And when we wait too long, we risk losing their interest altogether; religious literacy becomes a chore—for them and for us.

Precisely when and how you broach the subject with your child, though, will depend a lot on your child’s personality, not to mention your own worldview, the community in which you live, and the sorts of beliefs your child is most likely to encounter in talks with her peers. But, for purposes of planning, count on kicking things off around kindergarten. If you wait a little longer, that’s fine. But do keep in mind that the longer you wait, the harder the transition is likely to be. By eight, your child will probably have picked up a lot of things from peers; he might even be worried about what he’s hearing, or feel an inexplicable lack of belonging.

Here are some general guidelines.

Ages Four to Six. At this age, most kids are ready to start exploring ideas of spirituality. This is when blossoming imaginations begin welcoming supernatural ideas and when concepts like “good” and “evil” come into focus. It’s around this time, too, when inquisition replaces demand as the rhetorical tool of choice: “Why did this happen?” “What happens if someone does that?” “Why?” Around five, most children are being exposed to the reality that Mom and Dad don’t have exclusive control of the thought process: Kids at school also have ideas to share.

Ages Seven and Eight. If, by the time your kid turns seven or eight, you have made clear that faith is a subject you are open to discussing, you ought to hear the subject come up naturally from time to time. You child will likely enjoy thinking about how the world was made and how humans came to be. (Evolution fascinates children of this age.) They may want to discuss what they believe in comparison to what others believe and may surprise you with the depth of their thoughts on the matter. (If you are a believer, don’t forget to talk about non-belief, as well!) Talk a little about the belief systems of your extended family. Encourage your kids to share their own thoughts, whatever they may be. And don’t worry about distinguishing between religions at this early stage. Try pointing out what all religions have in common, rather than what sets them apart. All religions, for instance, have sacred texts. All have life-cycle celebrations. All have views of the afterlife. All have holiday celebrations. Once they grasp that, you can individualize religions a bit more.

Ages Nine to Eleven. At this point, religious talks will become commonplace. Expand on their knowledge. Work religious literacy into your conversations. Discuss some of the basic differences in religions and how those differences sometimes lead to conflict. Subjects like sin and hell are age-appropriate at this stage, as are discussions about “God’s will” versus “free will.” Look for opportunities to point out real-world examples of religion in books and architecture and clothing, for example. Take advantage of religious symbols in your community, lyrics in music, biblical clichés in your speech. Consider “celebrating” various religious holidays. If your child enjoys more philosophical discussions, you might find it fun to ask kids the question teacher Jim Morrison asks kids in his high school classroom: “Did God create man, or did man create God?”

Ages Twelve and Thirteen. I hate to break this to you, but you may be nearing the end of your influence, to a certain extent. As your child gets to be a teenager, she will likely begin to turn away from you and instead look to her friends for guidance and direction. That said, this is also the time when her critical thinking skills kick into high gear. Kids enjoy exploring the psychological and political aspects of religion more deeply at this age. Your talks might become increasingly more casual and unfiltered. Good! Just be sure to emphasize how much you value diversity and tolerance. Explain that religion is as much about culture as beliefs and that it’s important not to like or dislike people based on their religion or skin color or sexual orientation or any other identifying feature that makes them different. Sometimes those who are the most different from us have the most to offer us.

‘FACT, FICTION OR BELIEF?’

If you’re not sure your child is “ready” to discuss religious belief, try playing a game called “Fact, Fiction or Belief” to find out for sure. Define fact as anything that’s true; fiction as anything that’s made up; and belief as anything that some people think is fact and other people think is fiction. (For purposes of this game, all opinions, preferences, and tastes can be considered belief.) Then make statements and have your child label them accordingly. For instance, you might say: “The moon is in the sky.” (Fact!) “You like to eat rocks.” (Fiction!) “Pink is the best of all the colors.” (Belief!) Remember: Don’t try to make things too literal or complicated, or to inject actual religious beliefs into your examples. Just keep in mind the point of the game to see if your child can grasp the concept of belief—and have fun with it.