2 Corinthians 3:3-6

being made manifest that ye are an epistle of Christ, ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in tables that are hearts of flesh. And such confidence have we through Christ to God-ward: not that we are sufficient of ourselves, to account anything as from ourselves; but our sufficiency is from God; who also made us sufficient as ministers of a new covenant; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.