These things he said to me in tones of the deepest anger, so that I was confounded and exceedingly afraid of him, for his figure was altered so that a man could not endure his anger. But seeing me altogether agitated and confused, he began to speak to me in more gentle tones; and he said: “O fool, senseless and doubting, do you not perceive how great is the glory of God, and how strong and marvellous, in that He created the world for the sake of man, and subjected all creation to him, and gave him power to rule over everything under heaven?
If, then, man is lord of the creatures of God, and rules over all, is he not able to be lord also of these commandments? For,” says he, “the man who has the Lord in his heart can also be lord of all, and of every one of these commandments. But to those who have the Lord only on their lips, but their hearts hardened, and who are far from the Lord, the commandments are hard and difficult. Put, therefore, you who are empty and fickle in your faith, the Lord in your heart, and you will know that there is nothing easier or sweeter, or more manageable, than these commandments.
Return, you who walk in the commandments of the devil, in hard, and bitter, and wild licentiousness, and fear not the devil; for there is no power in him against you, for I will be with you, the angel of repentance, who am lord over him. The devil has fear only, but his fear has no strength. Fear him not, then, and he will flee from you.”
Source: The Pastor (or "The Shepherd") (New Advent)