2 Corinthians 4:2

But have renounced the hidden things of dishonesty
Or "shame"; this is a further account of the conduct of the first ministers of the Gospel, and very worthy of our imitation, and in which the apostle strikes at the different manner of behaviour in the false apostles: this may respect both doctrine and practice; they abhorred and rejected everything that was scandalous and reproachful to the Gospel of Christ; in simplicity and godly sincerity, not with fleshly wisdom, but by the grace of God, they had their conversation in the world; they were open and above board, both in principle and practice; the same men in public, as in private; they used no art to cover their doctrines, or hide their conversations; everything of this kind was detestable to them; whereas the false teachers took a great deal of pains to colour over both their sentiments and their lives; and "a shame it was to speak of the things that were done of them in secret", ( Ephesians 5:12 ) . Moreover, they were

not walking in craftiness;
they used no sly and artful methods to please men, to gain applause from them, or make merchandise of them; they did not lie in wait to deceive, watching an opportunity to work upon credulous and incautious minds; they did not, by good words and fair speeches, deceive the hearts of the simple; nor put on different forms, or make different appearances, in order to suit themselves to the different tempers and tastes of men, as did the false apostles:

not handling the word of God deceitfully.
They did not corrupt it with human doctrines, or mix and blend it with philosophy, and vain deceit; they did not wrest the Scriptures to serve any carnal or worldly purpose; nor did they accommodate them to the lusts and passions of men; or conceal any part of truth, or keep back any thing which might be profitable to the churches:

but by the manifestation of the truth, commending themselves to
every man's conscience in the sight of God;
that is, they with all plainness and evidence clearly preached the truth as it is in Jesus, presenting it to, and pressing it upon the consciences of men; where they left it, and to which they could appeal; and all this they did, in the sight and presence of the omniscient God, to whom they knew they must give an account of themselves and their ministry.