1 Corinthians 3:18

3:18 Guard against self-deception, each of you. ¹  If someone among you thinks he is wise in this age, let him become foolish so that he can become wise.

1 Corinthians 9:25

9:25 Each competitor must exercise self-control in everything. They do it to receive a perishable crown, but we an imperishable one.

¹ tn Grk “let no one deceive himself.”