My only hope in life and death
Question 60. How art thou righteous before God?
Answer: Only by a true faith in Jesus Christ; so that, though my conscience accuse me, that I have grossly transgressed all the commandments of God, and kept none of them, and am still inclined to all evil; notwithstanding, God, without any merit of mine, but only of mere grace, grants and imputes to me the perfect satisfaction, righteousness and holiness of Christ; even so, as if I never had had, nor committed any sin: yea, as if I had fully accomplished all that obedience which Christ has accomplished for me; inasmuch as I embrace such benefit with a believing heart.
(from the Heidelberg Catechism of 1563, question 60)