John Chrysostom

For not the fear of things to come only, he saith, but also those which have already happened allow us not to be slothful nor to slumber; but stir us up and impel us to these our labors on your behalf. And what are those things which have already happened? "That if one died for all, then all died." Surely then it was because all were lost, saith he. For except all were dead, He had not died for all. For here the opportunities of salvation exist; but there are found no longer. …

Homily 11 on 2 Corinthians ↗

Theophylact of Ohrid

The love of God, which He manifested in us, encompasses us and compels us to undergo dangers for Him, when we deliberate well within ourselves the following. Since He died for all, it is evident that we were all perishing, and that He died for the perishing and the dead in order to bring us to life.

Commentary on 2 Corinthians ↗

Augustine of Hippo

Paul said: "Therefore all died; and Christ died for all, in order that they who are alive may live no longer for themselves, but for him who died for them and rose again." All people, consequently, without a single exception, were dead through sin, original sin or original with personal sin superadded, either by ignorance of or conscious refusal to do what is right. …

City of God 20.6 ↗

Thomas Aquinas

Then when he says, For the love of Christ, the Apostle indicates the cause of his solicitude, namely, the love of Christ. In regard to this he does two things. First, he shows that he is pressed by the charity of Christ to procure the salvation of his neighbor; secondly, he indicates the source from which the charity of Christ is kindled (v. 14b). He says, therefore: I say that whether we be beside ourselves, it is for God; or whether we be sober, it is for you, i.e., for your benefit. …

Commentary on 2 Corinthians ↗