2 Peter 1:5

5And besides this. As it is a work arduous and of immense labor, to put off the corruption which is in us, he bids us to strive and make every effort for this purpose. He intimates that no place is to be given in this case to sloth, and that we ought to obey God calling us, not slowly or carelessly, but that there is need of alacrity; as though he had said, “Put forth every effort, and make your exertions manifest to all.” — For this is what the participle he uses imports.

Add to your faith virtue, or, Supply to your faith virtue. He shews for what purpose the faithful were to strive, that is, that they might have faith adorned with good morals, wisdom, patience, and love. Then he intimates that faith ought not to be naked or empty, but that these are its inseparable companions. To supply to faith, is to add to faith. There is not here, however, properly a gradation as to the sense, though it appears as to the words; for love does not in order follow patience, nor does it proceed from it. Therefore the passage is to be thus simply explained, “Strive that virtue, prudence, temperance, and the things which follow, may be added to your faith.” (149)

I take virtue to mean a life honest and rightly formed; for it is not here ἐνέργεια, energy or courage, but ἀρετὴ, virtue, moral goodness. Knowledge is what is necessary for acting prudently; for after having put down a general term, he mentions some of the principal endowments of a Christian. Brotherly-kindness, φιλαδελφία, is mutual affection among the children of God. Love extends wider, because it embraces all mankind.

It may, however, be here asked, whether Peter, by assigning to us the work of supplying or adding virtue, thus far extolled the strength and power of free-will? They who seek to establish free-will in man, indeed concede to God the first place, that is, that he begins to act or work in us; but they imagine that we at the same time co-operate, and that it is thus owing to us that the movements of God are not rendered void and inefficacious. But the perpetual doctrine of Scripture is opposed to this delirious notion: for it plainly testifies, that right feelings are formed in us by God, and are rendered by him effectual. It testifies also that all our progress and perseverance are from God. Besides, it expressly declares that wisdom, love, patience, are the gifts of God and the Spirit. When, therefore, the Apostle requires these things, he by no means asserts that they are in our power, but only shews what we ought to have, and what ought to be done. And as to the godly, when conscious of their own infirmity, they find themselves deficient in their duty, nothing remains for them but to flee to God for aid and help. (150)