Isaías 48

Isaías 48:20

Now my beloved, our will ought to keep pace with the grace of God and not fall short; lest while our will remains idle, the grace given us should begin to depart, and the enemy finding us empty and naked, … as was the case with him spoken of in the Gospel, from whom the devil went out. … For the departure from virtue gives place for the entrance of the unclean spirit. — FESTAL LETTERS 3:3