John Chrysostom

For He indeed translated us, but the Son furnished the cause. For what saith he? "Who delivered us out of the power of darkness." But the same is, "In whom we have the full redemption, even the forgiveness of sins." For had we not been forgiven our sins, we should not have been "translated." So here again the words, "In whom." And he said not "redemption," but "full redemption," so that we shall not fall any more, nor become liable to death.

Homily on Colossians 2 ↗

Theophylact of Ohrid

Lest you, having heard that the Father delivered us, should think that the Son showed nothing good, he says further that the Son granted us very much. For He is the source of our being brought into the Kingdom, since He granted us redemption, that is, the forgiveness of sins. For if we had not been redeemed and freed from them, we would not have been brought into the Kingdom. Thus He paved for us the way to the gift of the Father. …

Commentary on Colossians ↗

Irenaeus

And again, in his Epistle to the Galatians, he says: "But when the fulness of time had come, God sent forth His Son, made of a woman, made under the law, to redeem them that were under the law, that we might receive the adoption;" plainly indicating one God, who did by the prophets make promise of the Son, and one Jesus Christ our Lord, who was of the seed of David according to His birth from Mary; and that Jesus Christ was appointed the Son of God with power, according to the Spirit of holiness, by the resurrection from the dead, as …

Against Heresies 3.16.3 ↗

Thomas Aquinas

Then when he says, in whom we have redemption, he shows the way we have been transferred. For humanity in sin was held down in two ways: first, as a slave: "Every one who commits sin is a slave to sin" (Jn 8:34), and secondly, as deserving punishment and as turned away from God: "Your iniquities have made a separation between you and your God, and your sins have hid his face from you so that he does not hear" (Is 59:2). …

Commentary on Colossians ↗