I know imaging something does not make it so.
In your imagination you maybe a god but it doesn't make it true
Some anthropologist theorize that our imaginations are a survival mechanism in that we can imagine what may happen in the future and protect ourselves from future dangers. If we, as primitive people, see dangerous predators roaming around, we can imagine them killing us and then protect ourselves from them.
But imagining fairies and gods that will protect us from the predators is not such a good idea. It will make us less likely to take action to protect ourselves.
Imagination is really only useful if you have a bases in facts. That you believe in as many true things as possible will build a foundation for you to make good decisions.
Thinking your neighbors are witches is not likely to benefit you if you need your neighbors help.
It has no survival value unless you know some true facts about your neighbors and your society. If you know your neighbors property is valuable, that you can buy it for pennies if your neighbor is accused of being a witch, and nothing will happen to you if you accuse your neighbor of being a witch, then it may help you, if you want their property and can get them burned at the stake.
Same with gods. If you don't claim to believe in a Christian God can stop you from advancing in politics or other occupations, especially in the US. Not believing in Mormonism if you live in Utah, can be a career killer. But you have to know other true things to determine that.