1 Thessalonians 2:10

For our boasting is this: the testimony of our conscience, that in holiness and godly sincerity, not in fleshly wisdom but in the grace of God, we have conducted ourselves in the world, and especially toward you.

for our gospel did not come to you in word only, but also in power and in the Holy Spirit and with full assurance; just as you know what kind of men we proved to be among you for your sake.

For we never came with a flattering word, as you know, nor with a pretext for greed—God is witness—