The Ground of Perfect (amazing!) Hope

Question 60. How are 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 prone always to evil;  yet God, without any merit of mine,  and of mere grace,  grants and imputes to me  the perfect satisfaction,  righteousness and holiness of Christ;   as if I never committed or had any sin: and  had myself accomplished all the obedience which Christ has accomplished for me;  if only I accept such benefit with a believing heart. 

Heidelberg Catechism, question 60, 1563

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)