ISB ~ 2 Corinthians 1 v12

our conscience:Paul defends his sincerity against accusers who apparently questioned his motives for pursuing apostolic work.

not by earthly wisdom:Paul’s gospel does not stem from human ingenuity but from God, who revealed it through Christ. The marked difference between worldly knowledge and the wisdom of God was earlier explained in 1 Cor 1:18-4:7.

See word study:Wisdom at 1 Cor 1:20.