Augustine of Hippo

This is the combat we are challenged to, this the struggle with the flesh, this the struggle with the devil, this the struggle with the world. But let us be wary of confidence, because the one who instituted this contest does not watch his own champions, nor does he encourage us to rely on our own strength. Anyone relying on his own strength, you see, is relying, being clearly human, on the strength of a person; and accursed is everyone who rests his hope in humankind.