Augustine of Hippo

In order that we fall not away from the virtue of the soul, we ought to watch especially against those snares of the suggestions of the devil that we presume not of our own strength. For "cursed is everyone who places his hope in humankind." And who is he, but mortal? We cannot therefore truly say that the person who places his hope in humankind places it in himself. For this also is to "live after humankind," what is it but to "live after the flesh"? Whoever therefore is tempted by such a suggestion, let him hear, and if he has any Christian feeling, let him tremble. Let him hear, I say, "If you live after the flesh, you shall die."