Albert Barnes Commentary Romans 6:23

"For the wages of sin is death; but the free gift of God is eternal life in Christ Jesus our Lord." — Romans 6:23 (ASV)

For the wages of sin. The word translated here as wages (oqwnia)—properly denotes what is purchased to be eaten with bread, such as fish, meat, vegetables, etc. (according to Schleusner), and from there it came to mean the pay of the Roman soldier, because formerly it was the custom to pay soldiers in these items.

Therefore, it means that which a person earns or deserves; that which is their proper pay, or what they merit. As applied to sin, it means that death is what sin deserves—that which will be its proper reward. Death is thus called the wages of sin, not because it is an arbitrary, undeserved appointment, but for the following reasons:

1. Because it is its proper desert. Not a pain will be inflicted on the sinner that they do not deserve. Not a sinner will die who ought not to die. Sinners even in hell will be treated just as they deserve to be treated; and there is not to humankind a more fearful and terrible consideration than this. No one can conceive a more dreadful doom than for themselves to be treated forever just as they deserve to be.
2. This is the wages of sin because, like the pay of the soldier, it is just what was threatened. Ezekiel 18:4 states, The soul that sinneth, it shall die. God will not inflict anything more than was threatened, and therefore it is just.

Is death. This stands opposed here to eternal life and proves that one is just as enduring as the other.

But the gift of God. This is not the wages of humanity, not that which is due to us, but the mere gift and mercy of God. The apostle is careful to distinguish and to specify that this is not what humanity deserves, but that which is gratuitously conferred on us. (See the notes on Romans 6:15).

Eternal life. These are the same words that in Romans 6:22 are rendered everlasting life. The phrase is opposed to death and proves incontestably that death means eternal death. We may remark, therefore, on the following points:

1. That the one will be as long as the other.
2. As there is no doubt about the duration of life, so there can be none about the duration of death. The one will be rich, blessed, and everlasting; the other sad, gloomy, lingering, awful, and eternal.
3. If the sinner is lost, they will deserve to die. They will have their reward. They will suffer only what shall be the just due of sin. They will not be a martyr in the cause of injured innocence. They will not have the compassion of the universe in their favor. They will have no one to take their part against God. They will suffer just as much, and just as long, as they ought to suffer. They will suffer as the culprit pines in the dungeon, or as the murderer dies on the gallows, because this is the proper reward of sin.
4. Those who are saved will be raised to heaven, not because they merit it, but by the rich and sovereign grace of God. All their salvation will be ascribed to Him, and they will celebrate His mercy and grace forever.
5. It is fitting for us, therefore, to flee from the wrath to come. No one is so foolish and so wicked as the one who is willing to reap the proper wages of sin. No one is so blessed as the one who has a part in the mercy of God and who lays hold of eternal life.