John Chrysostom

"And might reconcile them both in one body unto God through the Cross." He saith, not merely "might reconcile," but "might reconcile thoroughly" indicating that heretofore human nature had been easily reconciled, as, e.g., in the case of the saints and before the time of the Law. "In one body," saith he, and that His own, "unto God." How is this effected? By Himself, he means, suffering the due penalty. "Through the cross having slain the enmity thereby." Nothing can be more decisive, nothing more expressive than these words. …

Homily on Ephesians 5 ↗

Gregory of Nyssa

Since then it was impossible that our life, which had been estranged from God, should of itself return to the high and heavenly place, for this cause, as saith the Apostle, He Who knew no sin is made sin for us, and frees us from the curse by taking on Him our curse as His own, and having taken up, and, in the language of the Apostle, "slain" in Himself "the enmity" which by means of sin had come between us and God,-(in fact sin was "the enmity")-and having become what we were, He through Himself again united humanity to God. …

Against Eunomius, Book 12 ↗

Theophylact of Ohrid

He did not say "reconcile" (καταλλάξη), but "fully reconcile" (άποκαταλλάξη), that is, reconcile again, showing that in ancient times too, through the law, human nature was being reconciled with God, but then, since through the transgression of the law the enmity was even more intensified, it again had need of reconciliation with God, which, as final, is rightly called reconciliation (άποκαταλλαγ). "In one body" — that is, in His own. …

Commentary on Ephesians ↗

Thomas Aquinas

When he states "and might reconcile both to God in one body," he discloses how both draw near to God. Concerning this he does two things: First, he treats of their reconciliation to God. Secondly, he writes of the manifestation of this reconciliation (2:17). …

Commentary on Ephesians ↗