On The Holy Trinity by St. Augustine
Chapter 12.--All, on Account of the Sin of Adam, Were Delivered into the Power of the Devil.
16. By the justice of God in some sense, the human race was delivered into the power of the devil; the sin of the first man passing over originally into all of both sexes in their birth through conjugal union, and the debt of our first parents binding their whole posterity. This delivering up is first signified in Genesis, where, when it had been said to the serpent, |Dust shalt thou eat,| it was said to the man, |Dust thou art, and unto dust thou shall return.| In the words, |Unto dust shalt thou return,| the death of the body is fore-announced, because he would not have experienced that either, if he had continued to the end upright as he was made; but in that it is said to him whilst still living, |Dust thou art,| it is shown that the whole man was changed for the worse. For |Dust thou art| is much the same as, |My spirit shall not always remain in these men, for that they also are flesh.| Therefore it was at that time shown, that he was delivered to him, in that it had been said to him, |Dust shall thou eat.| But the apostle declares this more clearly, where he says: |And you who were dead in trespasses and sins, wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of unfaithfulness; among whom we also had our conversation in times past, in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.| The |children of unfaithfulness| are the unbelievers; and who is not this before he becomes a believer? And therefore all men are originally under the prince of the power of the air, |who worketh in the children of unfaithfulness.| And that which I have expressed by |originally| is the same that the apostle expresses when he speaks of themselves who |by nature| were as others; viz. by nature as it has been depraved by sin, not as it was created upright from the beginning. But the way in which man was thus delivered into the power of the devil, ought not to be so understood as if God did this, or commanded it to be done; but that He only permitted it, yet that justly. For when He abandoned the sinner, the author of the sin immediately entered. Yet God did not certainly so abandon His own creature as not to show Himself to him as God creating and quickening, and among penal evils bestowing also many good things upon the evil. For He hath not in anger shut up His tender mercies. Nor did He dismiss man from the law of His own power, when He permitted him to be in the power of the devil; since even the devil himself is not separated from the power of the Omnipotent, as neither from His goodness. For whence do even the evil angels subsist in whatever manner of life they have, except through Him who quickens all things? If, therefore, the commission of sins through the just anger of God subjected man to the devil, doubtless the remission of sins through the merciful reconciliation of God rescues man from the devil.