Jeremiah 7[:22*, 23*], “For in the day that I brought your ancestors out of the land of Egypt, I did not speak to them or command them concerning burnt offerings and sacrifices. But this command I gave them, ‘Obey my voice, and I will be your God. . . .’ ” How may we suppose that the Israelites received this sermon, which seems to conflict openly with Moses? Clearly God had given the Fathers commands about burnt offerings and sacrificial victims. But Jeremiah condemns an opinion about sacrifices that God had not delivered, namely, that these acts of worship pleased God ex opere operato. However, concerning faith he adds that God had commanded: “Obey my voice,” that is, “believe that I am your God and that I want to be recognized when I show mercy and help you, for I do not need your sacrifices. Believe that I want to be God, the one who justifies and saves, not because of works but because of my Word and promise. Truly and from the heart seek and expect help from me.”
-- Apology of the Augsburg Confession, XXIV, para 28 from Robert Kolb et al., The Book of Concord : The Confessions of the Evangelical Lutheran Church (Minneapolis: Fortress Press, 2000), 263.