Suppose, about 15-20 thousand years ago, an extraterrestrial civilization conducted an experiment, as a result of which humanity appeared as a species. At first, this civilization had business on Earth, so along the way it helped people to develop.
Approximately 7-10 thousand years ago, the alien civilization flew away, but decided to periodically observe the results of their experiment (more precisely, to speak for us). Now about the most interesting part.
Imagine what they were constantly looking at? Endless wars, lack of development and moral degradation. I guess they decided to change the current situation by introducing religion.
That is, they organized a code of moral laws for people, which was supposed to stop all this chaos on Earth. Well, as we can see, this plan worked well. Their laws persist in the form of modern religions to this day.
I perfectly understand the fantastic nature of this version, but it has a sound logic. The concealment of the truth can also be easily explained if the Vatican, for example, knows it. After all, they cannot tell everyone that a few thousand years ago, aliens invented God in order to once again help people in development.
But if you look at this position from the side of a highly developed civilization trying to create a developed society, the situation changes dramatically. The introduction of religion allowed people to change morally, which eventually led to the development of civilization.