According to Osho, religions adopted repression to keep the priestly enterprise alive: by condemning natural thoughts and desires as ‘impure,’ priests explain ritual failures, manufacture guilt, and keep people obedient and dependent. Repression weakens intelligence, divides the mind, and sustains authority. When people accept their naturalness consciously, the priest loses his hold, so repression becomes the basic strategy for control and exploitation.
They call normal feelings bad so you feel guilty and need them, which keeps them in charge.