Upvote:2
I don't think children read comic books anymore, but 60 years ago I'd have understood it if it were described in terms of "alternate" universes, something like this:
Some event causes a divergence and splits off a separate world.
The people in each world have truths that would be considered false in many of the other worlds.
The child will understand the concept of groups of people believing things that completely contradict what other groups believe, without having to feel that any of them are "wrong".
What each group believes can then be taught and studied objectively for what it is, not for whether it is "true".