Martin Luther: Faith Is Not a Work

XVI. But you say: How can I trust surely that all my works are pleasing to God, when at times I fall, and talk, eat, drink and sleep too much, or otherwise transgress, as I cannot help doing? Answer: This question shows that you still regard faith as a work among other works, and do not set it above all works. For it is the highest work for this very reason, because it remains and blots out these daily sins by not doubting that God is so kind to you as to wink at such daily transgression and weakness. Aye, even if a deadly sin should occur (which, however, never or rarely happens to those who live in faith and trust toward God), yet faith rises again and does not doubt that its sin is already gone; as it is written I. John ii: "My little children, these things I write unto you, that ye sin not. And if any man sin, we have an Advocate with God the Father, Jesus Christ, Who is the propitiation of all our sins." And Wisdom xv: "For if we sin, we are Thine, knowing Thy power." And Proverbs xxiv: "For a just man falleth seven times, and riseth up again." Yes, this confidence and faith must be so high and strong that the man knows that all his life and works are nothing but damnable sins before God's judgment, as it is written, Psalm cxliii: "In thy sight shall no man living be justified"; and he must entirely despair of his works, believing that they cannot be good except through this faith, which looks for no judgment, but only for pure grace, favor, kindness and mercy, like David, Psalm xxvi: "Thy loving kindness is ever before mine eyes, and I have trusted in Thy truth"; Psalm iv: "The light of Thy countenance is lift up upon us (that is, the knowledge of Thy grace through faith), and thereby hast Thou put gladness in my heart"; for as faith trusts, so it receives. See, thus are works forgiven, are without guilt and are good, not by their own nature, but by the mercy and grace of God because of the faith which trusts on the mercy of God. Therefore we must fear because of the works, but comfort ourselves because of the grace of God, as it is written, Psalm cxlvii: "The Lord taketh pleasure in them that fear Him, in those that hope in His mercy." So we pray with perfect confidence: "Our Father," and yet petition: "Forgive us our trespasses"; we are children and yet sinners; are acceptable and yet do not do enough; and all this is the work of faith, firmly grounded in God's grace.

Luther, Martin (2009-10-04). A Treatise on Good Works (Kindle Locations 406-421). Public Domain Books. Kindle Edition.

--
Glory be to the Father, and to the Son : and to the Holy Ghost; As it was in the beginning, is now, and ever shall be : world without end. Amen.