From this, third, springs forth a genuine love for God, as Christ says here, “Her many sins are forgiven, because she loved much.” For if anyone rightly considers and believes with the whole heart that the Lord God has removed his great debt of sin by grace, he cannot help but love this faithful Father from the heart. On the other hand, when we still think of God in our hearts as a harsh debt collector, we cannot yet truly love Him. He is love itself (1 John 4:16,19). Therefore, He expects us to love Him in return; He cannot preserve this love among us without first forgiving us all our sins by grace, nor is there a better way for Him to preserve it. With this removal of debt, it is intended only that we should love Him. When that happens, then we finally begin again to experience that blessed fellowship that man had with the Lord God before the fall, a fellowship that consisted in love and love requited. Therefore Christ says in John 14:23, “If anyone loves Me, he will keep My word, and My Father will love him, and We will come to him and make Our dwelling with him.”
From this love springs the praise of God, and also willing obedience toward God and His commandments. As it says, “His commandments are not difficult” (1 John 5:3), that is, not difficult for the one who has received the forgiveness of sins through faith and has been renewed by the Holy Spirit, so that he serves the Lord God with willing obedience, from genuine love. This is why it says about such a man who loves God that “his works are done in God” (John 3:21), for they flow from faith in Christ and from love for God. May the faithful God also work this in us by the power of His Spirit. Amen.
(Sermon for Mary Magdalene-July 22, Postilla Volume 3 by Johann Gerhard, Repristination Press, page 113-114)