Earlier in this sermon, Augustine had cited Ps 143:9: “To you, O God, I will sing a new song; on a ten-stringed harp I will sing praises to you.” The ten-stringed harp he saw as a symbol of the decalogue, which led to this insistence on the inadequacy of fearful obedience, something he mistakenly thought marked the religion of the Old Testament.
Pay attention, beloved, so that I may say what the Lord suggests. The Jewish people received this law in the decalogue, but did not observe it. And those who did observe it did so out of fear of punishment, not out of love of righteousness: they were carrying the harp but were not singing. The harp is a pleasure for one singing, but a burden to one afraid. That’s why the old man either does not do the law or does it out of fear–not out of love of holiness, not out of delight in chastity, temperance, charity, but out of fear. He’s the old man, and the old man can sing the old song, but not a new song. To sing a new song, one has to become a new man. Listen, not to me, but to the Apostle, who tells us how one can become the new man: “Take off the old man and put on the new,” and lest anyone think this means taking something off and putting something else on, when in fact he is commanding a change in oneself, he added: “Therefore, laying aside lies, speak the truth” (Eph 4:22-25). Change your behavior, he said. You used to love the world: love God. You used to love worldly trifles, temporal pleasures: love your neighbor.
If you do these things out of love, you are singing a new song; if you do them out of fear, but still do them, you are indeed carrying the harp, but you’re not yet singing; and if you’re not doing them at all, you’re throwing the harp aside. It’s better at least to carry the harp than to throw it aside; but it’s better still to sing with pleasure than to carry it as if a burden. You haven’t yet reached a new song unless you’re singing with pleasure. One who carries it out of fear, is still in the old realm. Pay attention to what I’m saying, brothers and sisters. A person has not yet come to terms with his adversary if he is still acting out of fear; he’s afraid that God will come and condemn him. Chastity does not yet delight him; righteousness does not yet delight him; afraid of God’s judgment he refrains from the evil deed but does not condemn the powerful desires that rage within him. The good does not yet delight him; he doesn’t yet have the pleasure that would enable him to sing a new song. (Augustine, Sermon 9, 8; PL 38, 81-82)