John Chrysostom
That is, we say this not because we have despaired of you, or because we consider you full of thorns. We say it because we fear lest this happen.
It is better to make you afraid by words than to suffer grief in reality.
This especially shows Paul's wisdom. He did not say, "we think," "we suppose," "we expect," or "we trust." What did he say? "We hope."
So also in the Epistle to the Galatians he says, "I have confidence in you in the Lord, that you will think no otherwise" (Gal. 5:10).
He did not say, "you understand," but "you will think no otherwise." Since the Galatians were then very worthy of condemnation, the Apostle could not praise them for present deeds.
Therefore he praises them for the future: "You will not," he says, "think otherwise."
But here he praises the Hebrews for present deeds: "We hope that you are in a better state and hold fast to salvation, though we speak thus."