This is another post that I need to hear.
With gentleness [correct] those who are in opposition, if perhaps God may grant them repentance leading to the knowledge of the truth, and they may come to their senses and escape from the snare of the devil, having been help captive by him to do his will. (2 Tim. 2:25-26, NASB)
Repentance, according to this passage, requires revelation. God has to grant our opponents repentance that will lead to the knowledge of the truth.
This should be liberating for us. We do not have to make our arguments strong enough to convince the hard-hearted and foolish. We only have to make our arguments well enough, and with gentleness, to please God. God will take it from there.
Any of you who have ever had a word from God lodge in your heart knows how unshakeable the conviction of the Lord is. That word will pierce like a thorn until you either give in or make a conscious choice to turn your back on God and choose evil.
One final note. This is not the only place that says repentance must be given by God:
They quieted down and glorified God, saying, "Well, then, God has granted to the Gentiles also the repentance that that leads to life." (Acts 11:18b, NASB)