[Daniel 5:19] "'He slew whomever he would and smote to death whomever he wished to; those whom he wished he set on high, and brought low whomever he would.'" Thus he sets forth the example of the king's great-grandfather, in order to teach him the justice of God and make it clear that his great-grandson too was to suffer similar treatment because of his pride. Now if Nebuchadnezzar slew whomever he would and smote to death whomever he wished to; if he set on high those whom he would and brought low whomever he wished to, there is certainly no Divine providence or Scriptural injunction behind these honors and slayings, these acts of promotion and humiliation. But rather, such things ensue from the will of the men themselves who do the slaying and promoting to honor, and all the rest. If this be the case, the question arises as to how we are to understand the Scripture: "The heart of a king reposes in the hand of God; He will incline it in whatever direction He wishes" (Proverbs 21:1). Perhaps we might say that every saint is a king, for sin does not reign in his mortal body, and his heart therefore is kept safe, for he is in God's hand (Romans 6:1-23). And whatever has once come into the hand of God the Father, according to the Gospel, no man is able to take it away (John 10:28). And whoever is taken away, it is understood that he never was in God's hand at all.
If Christ were to die again, it follows that those who have died with him and who will be raised with him will also die again along with him! Therefore the apostle makes it clear that Christ will never die again, so that those who will live with him may be sure of having eternal life.…Paul was right to say that “death no longer has dominion over him.” For he will never again give himself up to the rule of the tyrant, nor will he again empty himself in order to take the form of a servant and be made obedient unto death. Nor will he ever again endure the rule of the tyrant and of death in the form of a servant, even though he assumed it voluntarily and not because he was forced into it.
In taking upon Him manhood, He gave a testimony in the world, wherein also having suffered, He freed us by His blood from sin; and having vanquished hell, He was the first who rose from the dead and "death shall have no more dominion over Him."
And notice again his undauntedness, and how he makes the thing good from opposite grounds. Since then it was likely that some would feel perplexed at the Cross and the Death, he shows that this very thing is a ground for feeling confident henceforward.
For suppose not, he says, because He once died, that He is mortal, for this is the very reason of His being immortal. For His death has been the death of death, and because He did die, He therefore does not die. For even that death (Romans 6:10)
We shall not fear the second death if we have died willingly. Or it may mean: “You cannot be baptized a second time because Christ cannot be crucified for you a second time,” as Paul writes to the Hebrews. He does not say that these people cannot repent, but he does not allow them to repeat their baptism.
Though Christ is now risen from the dead, and death has no more power over him, yet living in himself immortal and incorruptible he is again immolated for us in the mystery of the holy sacrifice. Where his body is eaten, there his flesh is distributed among the people for their salvation. His blood no longer stains the hands of the godless but flows into the hearts of his faithful followers.
[AD 420] Jerome on Romans 6:1-23