Heidelberg Catechism.
How are you right with God?

Only by true faith in Jesus Christ (1).
Even though my conscience accuses me
of having grieviously sinned against all God's commandments
and of never having kept any of them (2),
and even though I am still inclined toward all evil (3),
nevertheless - without my deserving it at all (4),
out of sheer grace (5),
God grants and credits to me
the perfect satisfaction, righteousness, and holiness of Christ (6),
as if I had never sinned or been a sinner,
as if I had been as perfectly obedient
as Christ was obedient for me (7).

All I need to do is to accept this gift of God with a believing heart (8).

1. Romans 3 v21-28; Ephesians 2 v8-9.
2. Romans 3 v9-10.
3. Romans 7 v23.
4. Titus 3 v4-5.
5. Romans 3 v24; Ephesians 2 v8.
6. Romans 4 v3-5; 2 Corinthians 5 v17-19; 1 John 2 v1-2.
7. Romans 4 v24-25; 2 Corinthians 5 v21.
8. John 3 v18; Acts 16 v30-31.