7 But O free man, called unto liberty, be weary, be weary of your servitude to such mistresses as these. Acknowledge your Redeemer, your Deliverer. Serve Him, He enjoins easier things, He enjoins not things contrary one to another. I am bold further to say; avarice and luxuriousness did enjoin upon you contrary things, so that you could not obey them both; and one said, “Keep for yourself, and consult for the future;” the other said, “Spend freely, do well to your own soul.”
Now let your Lord and your Redeemer come forth, and He shall say the same, and yet no contrary things. If you will not, His house has no need of an unwilling servant. Consider your Redeemer, consider your Ransom. He came to redeem you, He shed His Blood. Dear He held you whom He purchased at so dear a price. Thou dost acknowledge Him who bought you, consider from what He redeems you. I say nothing of the other sins which lord it proudly over you; for you were serving innumerable masters.
I speak only of these two, luxuriousness and avarice, giving you contrary injunctions, hurrying you into different things. Deliver yourself from them, come to your God. If you were the servant of iniquity, be now the servant of righteousness. The words which they spoke to you, and the contrary injunctions they gave you, the very same you hear now from your Lord, yet are His injunctions not contrary. He does not take away their words, but he takes away their power. What did avarice say to you? “Keep for yourself, consult for the future.” The word is not changed, but the man is changed. Now, if you will, compare the counsellors. The one is avarice, the other righteousness.
Source: Sermons on Selected Lessons of the New Testament (New Advent)