What are the reasons for the emergence of religious dissidence in the USSR? How did it manifest itself?

The reason for the emergence of religious dissidence was that the communists in power in the USSR tried to impose on people that their ideology is the only correct one, that no belief in God is needed or correct. It manifested itself in the fact that the population united in groups or individually carried out propaganda. Most of these people belonged to the intelligentsia. Also, the belief in God was “underground”, they tried not to advertise it.