John Chrysostom

"Nevertheless, He left not Himself without witness, in that He did good, giving you rain from heaven, and fruitful seasons, filling your hearts with food and gladness." See how covertly he puts the accusation "in that He did good," etc. And yet if God did this, He could not have "let them alone;" on the contrary, they ought to be punished, for that, enjoying so great benefits, they had not acknowledged Him, not even as their feeder. …

Homily on Acts 31 ↗

Theophylact of Ohrid

"Although He did not cease to bear witness about Himself." He says this because in every generation He performed such works as led people to the truth. Without forcing free will, the Lord allowed all people to walk according to their own judgment, but He Himself constantly performed such works from which they, as rational beings, could come to know the Creator. The apostle calls even the annual rains witnesses of Him.

Commentary on Acts ↗

Cosmas Indicopleustes

And yet He has not left them without a witness to Himself, that He was working for their good and taking thought for it beforehand, for He manifested to them some tokens of His goodness, some four hundred years or more before the coming of Christ, in the days of Alexander the Macedonian, long after the Trojan war, when the Greeks were still flourishing. …

The Christian Topography, Book 12 ↗