On the Reasons of the Holy Spirit, Book II

Some, akin to the Nestorians, say that there is one person, but that the human nature was transmuted into God; this is a very grave error. For since the divinity is incorporeal, it is impossible for it to be made from a body. The impiety of the Basilidians agrees with the Jews and Muhammad. For all of them say that the redemption of human nature is not a work. The Jews diminish the gravity of Adam's sin and dare to call it a minor sin, while it is established that however slight the deviation (to grant them their opinions) from the right judgment of the mind and the precept of God may have been, because it was committed against the infinite, it deserves an infinite expiation. But to attain the beatitude for which man was born, with any vice or guilt whatsoever, is altogether impossible. Yet, as I said, so that the world was not made in vain, it must be attained, not by the works of man alone, nor by mercy alone, but by the work of both mercy and justice concurring in one nature. Basilides and Marcus, together with Muhammad, denying that He was nailed to the cross and consumed by a most shameful death, say that He came in vain. For unless He had washed away the punishments due to the whole mass of human nature in the body and had satisfied the punishments of God's justice, the world would have been made in vain, or God would possess justice in Himself in vain. In truth, the death of Jesus Christ is the scope of the whole world. For no creature attains its natural end at all, unless man, to whom all things serve, attains salvation through the death of Jesus Christ and restoration through His resurrection. For He would have come hither in vain, unless He had risen immediately or shortly after death, so that those whom He came to redeem, having awaited the mercy of God for many years, might also