II Corinthians 3:5-6
5 Not that we are adequate in ourselves to consider anything as coming from ourselves, but our adequacy is from God, 6 who also made us adequate as servants of a new covenant, not of the letter but of the Spirit; for the letter kills, but the Spirit gives life.
II Corinthians 4:5
For we do not preach ourselves but Christ Jesus as Lord, and ourselves as your bond-servants for Jesus’ sake.