Presumptive self-confidence may look like faith, but it has a very different spiritual root (Jer. 17:5-10). Faith and presumption look alike because both qualities are characterized by confidence, but faith begins in the recognition and acceptance of our total human weakness. It relies solely on God and his gracious willingness to empower us.

Presumption, on the other hand, is a reliance on human moral abilities and religious accomplishments, on visible securities. It ultimately relies on human will power to serve God and people.

— Rose Marie Miller, From Fear to Freedom, pp. 15-16.