Organized religion is nothing more than a way to control the masses. It tells its followers that there is one single, true reality—its own—and that it cannot be questioned; in this way, human beings lose one of their most important faculties: the ability to think and reason. Humanity has managed to build civilizations precisely because it lacked all the answers—because individuals had to interpret the real world in their own unique ways, and then weave those various perspectives together. If, before you even begin to reflect on anything, you are told that all the answers have already been provided, the human being becomes less complex, because they will never have to strive to find those answers for themselves.
Furthermore, organized religion is typically hierarchical, with a select few ending up in control of everything. They exploit the faith of their followers for their own benefit, altering religious laws to suit their own interests—all while remaining beyond question, thanks to the blind faith of the people.