Theophylact of Ohrid

Again he points to the manner of the reconciliation, namely – "in the body." In what way? Did He only undergo scourging and striking? No, but He also died the most shameful death. Again he points to another benefaction, saying now the same thing that he expressed above with the words: "who made you capable." For not only, he says, did He free us from sins, but He also granted holiness, not an ordinary one, but holiness before His face, and blamelessness, and innocence, so that we would commit nothing that would deserve even simple …

Commentary on Colossians ↗

Augustine of Hippo

Now some of these passages exhort men who are running their course that they run perfectly; others refer to the end thereof, that men may reach forward to it as they run. He, however, is not unreasonably said to walk blamelessly, not who has already reached the end of his journey, but who is pressing on towards the end in a blameless manner, free from damnable sins, and at the same time not neglecting to cleanse by almsgiving such sins as are venial. …

Concerning Man's Perfection in Righteousness ↗

Jerome

For flesh is defined one way, the body another; all flesh is body, but not every body is flesh. Flesh is properly what is comprised in blood, veins, bones, and sinews. Although the body is also called flesh, yet sometimes it is designated ethereal or aërial, because it is not subject to touch and sight; and yet it is frequently both visible and tangible. A wall is a body, but is not flesh; a stone is a body, but it is not said to be flesh. Wherefore the Apostle calls some bodies celestial, some terrestrial. …

To Pammachius Against John of Jerusalem ↗

Thomas Aquinas

Then when he says, he has now reconciled, he mentions the benefits coming from Christ. The first of these is reconciliation in his body; and so he says, he has now reconciled in his body of flesh. He says, his body of flesh, not because his body and his flesh are not the same, but to show that Christ took a real body: "And the Word became flesh and dwelt among us" (Jn 1:14). A body of flesh, that is, a mortal body: "God, sending his own Son in the likeness of sinful flesh and of sin, has condemned sin in the flesh" (Rom 8:3). …

Commentary on Colossians ↗