Engels
Ludwig Feuerbach and the End of Classical German Philosophy
(orig. 1886)
Part 2: Materialism
... From the very early times when men, still completely ignorant of the structure of their own bodies, under the stimulus of dream apparitions came to believe that their thinking and sensation were not activities of their bodies, but of a distinct soul which inhabits the body and leaves it at death — from this time men have been driven to reflect about the relation between this soul and the outside world. ... The quandry arising from the common universal ignorance of what to do with this soul... and not religious desire for consolation, led in a general way to the tedious notion of personal immortality. In an exactly similar manner, the first gods arose through the personification of natural forces. And these gods in the further development of religions assumed more and more extramundane form, until finally by a process of abstraction, I might almost say of distillation,... there arose in the minds of men the idea of the one exclusive God of the monotheistic religions.
