9. Behold this good inclination or comforting trust, or free presumption toward God, or whatever you may call it, in the Scriptures is called Christian faith and a good conscience,
which man must have if he desires to be saved. But it is not obtained by human works and precepts, as we shall see in this example, and without such a heart no work is good. Therefore be on your guard, there are many lecturers who want to teach faith and conscience, and know less about them than a common blockhead. They think it is a sleepy, lazy thing in the soul, that it is enough for the heart to believe that God is God. But here you observe what a thoroughly living and powerful thing faith is. It creates wholly a new heart, a new man, who expects all grace from God. Therefore it urges to walk, to stand, makes bold to cry and pray in every time of trouble.
Luther's Gospel sermon on Luke 17 - The Ten Lepers
