2 Corinthians 4:2
But have renounced the hidden things of dishonesty, not walking in craftiness, nor handling the word of God deceitfully; but by manifestation of the truth commending ourselves to every man's conscience in the sight of God.
Torrey's Topical Textbook—AKJV

2 Corinthians 6:7,8
By the word of truth, by the power of God, by the armor of righteousness on the right hand and on the left,
Torrey's Topical Textbook—AKJV

2 Corinthians 7:14
For if I have boasted any thing to him of you, I am not ashamed; but as we spoke all things to you in truth, even so our boasting, which I made before Titus, is found a truth.
Torrey's Topical Textbook—AKJV