If myths and stories impact on humans in a way that adds to their meaning and experience of their life, then them believing it has meaning is a natural consequence. Neither Jung not Peterson argued for a theistic religions fiction to be true, just of the psychological impacts that belief in a God, myths etc has. If you only believed what you could prove, of that we live a meaningless existence on a rock which will eventually be burned up by its star then it feels a lot hollower than a purposeful design. That's not to say it's true, but I think more people feel that than not and to believe in the nihilistic view is arguably harmful to the psyche. Which I believe is what jung and Peterson are getting at, of the benefits of such a belief. Not that any religion etc is correct, I believe Jung talked about how when he killed a God they appeared elsewhere, as a guide for the psyche. Nature for example could be seen as a God in the current zeitgeist with pollution and mankind's greed it's demon.