From The Apology of the Augsburg Confession, Article V: Love and Fulfilling the Law:
But the virtue that justifies receives Christ, which brings to us Christ’s merits, by which we receive grace and peace from God. This virtue is faith. As it has often been said, faith is not just knowledge. But it is willing to receive or take hold of those things that are offered in the promise about Christ. 107 Furthermore, this obedience toward God (i.e., to want to receive the offered promise) is no less a divine service (latreia) than is love. God wants us to believe Him and to receive from Him blessings. He declares this to be true divine service.108 The adversaries base justification on love because they everywhere teach and require the righteousness of the Law. We cannot deny that love is the Law’s highest work. Human wisdom gazes at the Law and seeks justification in it. So the scholastic doctors, great and talented men, proclaim love as the Law’s highest work and base justification on this work. Deceived by human wisdom, they did not look upon the uncovered, but upon the veiled face of Moses, just like the Pharisees, philosophers, and followers of Muhammad. 109 But we preach the foolishness of the Gospel, in which another righteousness is revealed: for Christ’s sake as the Atonement, we are counted righteous when we believe that God has been reconciled to us for Christ’s sake. Neither are we ignorant about how far distant this teaching is from the judgment of reason and the Law. Nor are we ignorant that the Law’s teaching about love makes a much greater show. For it is wisdom. But we are not ashamed of the Gospel’s foolishness. We defend this truth for the sake of Christ’s glory and ask Christ, by His Holy Spirit, to help us so that we may be able to make this clear and obvious.
Concordia: The Lutheran Confessions, Edited by Paul Timothy McCain (St. Louis, MO: Concordia Publishing House, 2005), 116.