Therefore God has been gracious to us and has given us a Comforter to counteract this spirit of terror—a Comforter, who, as God Himself, is much stronger with His comfort than the devil is with his terror. And now when the devil also comes along with God’s Law, advances against your works and your life, and shatters these so thoroughly that even your good works appear to be evil and condemned—an art in which he is a master and an excellent theologian—the Holy Spirit, on the other hand, will come and whisper consolingly to your heart: “Be of good cheer and unafraid. Go, preach, do what you have been commanded to do; and do not fear the terrors of sin, death, or the devil, even if these terrors present themselves in the name of God.
God does not want to be angry with you, nor does He want to reject you; for Christ, God’s Son, died for you. He paid for your sins; and if you believe in Him, these will not be imputed to you, no matter how great they are. Because of your faith your works are pleasing to God; they are adjudged good and well done even though weakness does creep in. Why do you let your sins be falsely magnified? Christ, your Righteousness, is greater than your sins and those of the whole world; His life and His consolation are stronger and mightier than your death and hell.”
Martin Luther, Luther’s Works, Vol. 24: Sermons on the Gospel of St. John: Chapters 14-16, ed. Jaroslav Jan Pelikan, Hilton C. Oswald, and Helmut T. Lehmann, vol. 24 (Saint Louis: Concordia Publishing House, 1999), 291–292.