If it is obvious that you are not the victor but merely an instrument, as it were, and that it is the Lord who is victorious in you, and that you receive the title of victor as a free gift, then what can hinder you from asking at all times for that same strength, what can hinder you from winning the same victories while you give thanks to God for this? Have you not heard, O man, how many champions from the foundation of the world and the beginnings of time have fallen from the height of their struggle because they did not give thanks for this grace?
Homily 37 (p. 315).