It is not God who made man in his image: it is man who made God in his.

Supports

Feuerbach, Freud · The Essence of Christianity, chs. I–II · 1841

Consider God's attributes: power, knowledge, goodness, justice, raised to the infinite. They are, trait for trait, human qualities stripped of our limits: man contemplates himself in them, magnified.
Now this movement of projection is fully explained by human causes: the fear of death, the desire that justice be done, the need for consolation and for a protecting father. No God is needed to understand why humans believe in God.
A hypothesis that can be accounted for without supposing it true, and that answers our desires so exactly, loses its credit: what we would have invented from scratch would look precisely like this.

Therefore So God is not in heaven but in us: a projection of humanity, whose making the history of religions describes.

How far does this reasoning convince you?

Not at all

Entirely

Put to the test

Problem