Sigmund Freud was no friend of religion.

The whole thing is so patently infantile, so foreign to reality, that to anyone with a friendly attitude to humanity it is painful to think that the great majority of mortals will never be able to rise above this view of life.Sigmund Freud

Psychoanalysis emerged at a time of transition, when religious doctrines were starting to lose their hold.

A godless Jew

Although himself a Jew, he identified as an atheist.