On this account, therefore, the Lord Himself, who is Emmanuel from the Virgin, is the sign of our salvation, since it was the Lord Himself who saved them, because they could not be saved by their own instrumentality; and, therefore, when Paul sets forth human infirmity, he says: “For I know that there dwelleth in my flesh no good thing,” showing that the “good thing” of our salvation is not from us, but from God. And again: “Wretched man that I am, who shall deliver me from the body of this death?” Then he introduces the Deliverer, [saying,] “The grace of Jesus Christ our Lord.” And Isaiah declares this also, [when he says:] “Be ye strengthened, ye hands that hang down, and ye feeble knees; be ye encouraged, ye feeble-minded; be comforted, fear not: behold, our God has given judgment with retribution, and shall recompense: He will come Himself, and will save us.” Here we see, that not by ourselves, but by the help of God, we must be saved.

Irenaeus of Lyons. 1885. “Irenæus against Heresies.” In The Apostolic Fathers with Justin Martyr and Irenaeus, edited by Alexander Roberts, James Donaldson, and A. Cleveland Coxe, 1:450. The Ante-Nicene Fathers. Buffalo, NY: Christian Literature Company.