Here is a nice little gem from Martin Luther which comes from Treasury of Daily Prayer.
He is not righteous who does much, but he who, without work, believes much in Christ.
For the righteousness of God is not acquired by means of acts frequently repeated, as Aristotle taught, but it is imparted by faith, for “He who through faith is righteous shall live” (Rom. 1[:17]), and “Man believes with his heart and so is justified” (Rom. 10[:10]). Therefore I wish to have the words “without work” understood in the following manner: Not that the righteous person does nothing, but that his works do not make him righteous, rather that his righteousness creates works. For grace and faith are infused without work works. After they have been imparted the works follow. Thus Rom. 3[:20] states, “No human being will be justified in His sight by works of the law,” and, “For we hold that man is justified by faith apart from works of law” (Rom. 3[:28]). In other words, works contribute nothing to justification. Therefore man knows that works which he does by such faith are not his but God’s. For this reason he does not seek to become justified or glorified through them, but seeks God. His justification by faith in Christ is sufficient to him. Christ is his wisdom, righteousness, etc., as I Cor. 1[:30] has it, that he himself may be Christ’s vessel and instrument.
Taken from Treasury of Daily Prayer, p. 1004
Quoted from “Heidelberg Disputation”, pp.55-56 in vol. 31 of Luther’s Works, American Edition.