John 1:17

For the law was given through Moses; grace and truth came through Jesus Christ.

Romans 5:20-21

Law came in, that the trespass might increase. But where sin increased, grace abounded all the more,

Romans 15:8-9

For I tell you that Christ has become a servant of the circumcised to show God's truth, to confirm the promises made to the patriarchs,

Ephesians 1:7

In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace

Ephesians 2:4-7

But God, who is rich in mercy, because of his great love with which he loved us,

Treasury of Scripture Knowledge

Summary

But thou, O Lord, art a God full of compassion, and gracious, longsuffering, and plenteous in mercy and truth.

Bible References

But thou

Romans 5:20
Law came in, that the trespass might increase. But where sin increased, grace abounded all the more,
Ephesians 1:7
In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace
Ephesians 2:4
But God, who is rich in mercy, because of his great love with which he loved us,