But, in truth, He has even called the flesh to the resurrection, and promises to it everlasting life. For where He promises to save man, there He gives the promise to the flesh. For what is man but the reasonable animal composed of body and soul? Is the soul by itself man? No; but the soul of man. Would the body be called man? No, but it is called the body of man. If, then, neither of these is by itself man, but that which is made up of the two together is called man, and God has called man to life and resurrection, He has called not a part, but the whole, which is the soul and the body. Since would it not be unquestionably absurd, if, while these two are in the same being and according to the same law, the one were saved and the other not? And if it be not impossible, as has already been proved, that the flesh be regenerated, what is the distinction on the ground of which the soul is saved and the body not? Do they make God a grudging God?
But He is good, and will have all to be saved. And by God and His proclamation, not only has your soul heard and believed on Jesus Christ, and with it the flesh, but both were washed, and both wrought righteousness. They make God, then ungrateful and unjust, if, while both believe in Him, He desires to save one and not the other. Well, they say, but the soul is incorruptible, being a part of God and inspired by Him, and therefore He desires to save what is peculiarly His own and akin to Himself; but the flesh is corruptible, and not from Him, as the soul is. Then what thanks are due to Him, and what manifestation of His power and goodness is it, if He purposed to save what is by nature saved and exists as a part of Himself? For it had its salvation from itself; so that in saving the soul, God does no great thing. For to be saved is its natural destiny, because it is a part of Himself, being His inspiration. But no thanks are due to one who saves what is his own; for this is to save himself. For he who saves a part himself, saves himself by his own means, lest he become defective in that part; and this is not the act of a good man. For not even when a man does good to his children and offspring, does one call him a good man; for even the most savage of the wild beasts do so, and indeed willingly endure death, if need be, for the sake of their cubs.
But if a man were to perform the same acts in behalf of his slaves, that man would justly be called good. Wherefore the Saviour also taught us to love our enemies, since, says He, what thank have you? So that He has shown us that it is a good work not only to love those that are begotten of Him, but also those that are without. And what He enjoins upon us, He Himself first of all does.
[St. Justin Martyr, On the Resurrection]