Paul asks his question again, almost word for word from the top of the chapter, and answers it the same way: 15"Are we to sin because we are not under law but under grace? By no means!" But this time he pushes further, because grace reassigns ownership. 16"if you present yourselves to anyone as obedient slaves, you are slaves of the one whom you obey?" Paul's readers lived in a world where slavery was familiar, and they knew what total ownership meant. He allows no neutral middle ground. Everyone belongs to a master, either of sin, which leads to death, or of obedience, which leads to righteousness.
Then comes thanks to God, and what follows describes something that has already happened: once slaves of sin, they 17"have become obedient from the heart." The allegiance runs to the heart because it rests on a change of ownership. Freedom, in Paul's vocabulary, means being set free from sin and becoming slaves of righteousness. It means trading one master for the right one.
Paul pauses to explain his own metaphor. He says, 19"I am speaking in human terms." Slave language only approximates what happened at the cross, but it is the picture his readers will understand, and he uses it without apology. The same members that once served impurity now belong to another master: 19"present your members as slaves to righteousness."
Then Paul asks them to remember. 20"When you were slaves of sin, you were free in regard to righteousness." That old freedom sounds attractive until Paul names its harvest. 21"What fruit were you getting at that time from the things of which you are now ashamed?" Shame is the honest verdict every believer reaches about the old master's service. 21"The end of those things is death." The word Paul uses for "wages" in verse 23 was the term for a soldier's pay. Sin is a commanding officer, and it pays every soldier under its command exactly what he signed up for. The check clears, always. It is drawn on an account that ends in death.
Against that, Paul sets a different kind of ending. Now that you have been set free from sin and have become slaves of God, 22"the fruit you get leads to sanctification and its end, eternal life." One master pays wages. The other gives a gift.
The last sentence sums up the chapter, and it sets wages against a free gift of eternal life in Christ Jesus our Lord. One side is earned, calculated, exactly proportioned to what was owed. The other is given, out of all proportion to what anyone could work for, and it is offered in Christ Jesus to people who, a few verses earlier, were called slaves.
Ask whether you have been imagining yourself neutral, a self answerable to no one. Look at the habits you obey without deciding to. Paul's question is which master they serve, and his good news is that a new one has already bought you.
Prayer
Father, thank you that we are no longer serving a master who pays only in death. Forgive us for the moments we still obey sin's old commands out of habit, as though we belonged to it still. Let our obedience come from the heart, and keep presenting our hands, our minds, and our whole selves to you as instruments of righteousness. Let the fruit be the eternal life you promised in Christ Jesus our Lord. Amen.