15 Do not resist evil, for he is evil from the Evil One, whoso resists evil. Keep not back anything from any man, that if he perishes you may not be blamed. Change not your respect for a man's person, according to goods and possessions. Make all things as though they were not and God alone were in being. If you shall ask of your neighbour and he shall not give you according to your wish, see that you say not in anger a word that is full of bitterness. Oppose not [fit] seasons, for many are the changes. Put sorrow far from your flesh, and sadness from your thoughts; save only that for your sins you should be constant in sadness. Cease not from labour, not even though you be rich, for the slothful man gains manifold guilt by his idleness.
Source: On Admonition and Repentance (New Advent)