Few issues can make a person cringe as much as slavery. It’s not the subject of casual, carefree conversation. Whether one refers to past injustices or modern evils, the subject of slavery is usually met with angst and contempt. With that in mind, slavery isn’t the metaphor we tend to reach for to communicate encouraging spiritual truth.
Not so with God’s Word. Scripture repeatedly uses the imagery of slavery to poignantly describe unrepentant man’s relationship with sin (John 8:34; 2 Peter 2:19). It’s an apt metaphor—sin marks us as its own, it rules without mercy, binds us in chains, and won’t let us go.
But in Romans 6:17-18, Paul writes about a different kind of slavery for believers. Contrasting our new position in Christ against our former slavery to sin, he writes,
But thanks be to God that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed, and having been freed from sin, you became slaves of righteousness (emphasis added).
Dead to Sin
The key to understanding what it means to be slaves of righteousness is that we have first been set free from our slavery to sin. Earlier in the chapter, Paul asks his readers a pointed rhetorical question: “How shall we who died to sin still live in it?” (Romans 6:2).
In his book The Gospel According to the Apostles, John MacArthur explains that the Greek word translated “died to sin”
speaks of a historical fact referring to our death in the death of Christ. Because we are “in Christ” (Romans 6:11; 8:1), and He died in our place (Romans 5:6-8), we are counted dead with Him. We are therefore dead to sin’s penalty and dominion. Death is permanent. Death and life are incompatible. So the person who has died to sin cannot continue living in iniquity. Certainly we can commit sins, but we do not live anymore in the dimension of sin and under sin’s rule. Sin is contrary to our new disposition. “No one who is born of God practices sin,” according to John, “because His seed abides in him; and he cannot sin, because he is born of God” (1 John 3:9). It is not merely that we should not continue to live in unbroken sin but that we cannot. John MacArthur, The Gospel According to the Apostles, 113-114
John adds that “dying to sin implies an abrupt, irreversible, wholesale break with the power of sin.” 114
Justified and Sanctifying
In the moment of salvation, God breaks the power of sin in our lives as part of His work of regeneration (Ezekiel 36:26-27; Romans 6:6-7). But we are also instantaneously justified in God’s sight, free from the guilt and punishment of our sin. In effect, the slate is wiped clean. John MacArthur explains it this way:
In its theological sense, justification is a forensic, or purely legal, term. It describes what God declares about the believer, not what He does to change the believer. In fact, justification effects no actual change whatsoever in the sinner’s nature or character. Justification is a divine judicial edict. It changes our status only, but it carries ramifications that guarantee other changes will follow. 89
Those changes are called sanctification. We’ve already defined God’s sanctifying work, but it’s important to consider how it differs from justification. As John explains,
Justification is distinct from sanctification because in justification God does not make the sinner righteous; He declares that person righteous (Romans 3:28; Galatians 2:16). Justification imputes Christ’s righteousness to the sinner’s account (Romans 4:11); sanctification imparts righteousness to the sinner personally and practically (Romans 6:1-7; 8:11-14). Justification takes place outside sinners and changes their standing (Romans 5:1-2); sanctification is internal and changes the believer’s state (Romans 6:19) Justification is an event, sanctification a process. The two must be distinguished but can never be separated. God does not justify whom He does not sanctify, and He does not sanctify whom He does not justify. Both are essential elements of salvation. 90
Put simply, “Justification frees us from the guilt of sin, sanctification from the pollution of sin.” 109
Dying to our sin is then the first step in the process of sanctification. It’s the process through which the Spirit refines us, killing off the remnants of our former selves—our sinful habits, tastes, and desires—and replacing them with godly affections and inclinations. It’s the active, ongoing transformation of your heart, mind, and entire self, beginning at the moment of salvation and continuing throughout the remainder of your life.
When we are born again [regeneration], God not only declares us righteous [justification], but He also begins to cultivate righteousness in our lives [sanctification]. Thus salvation is not only a forensic declaration; it is a miracle of conversion, of transformation. There is no such thing as a true convert to Christ who is justified but who is not being sanctified. . . . As the sinful, unregenerate person cannot help manifesting his or her true character, neither can the regenerate person.  114
As slaves of righteousness, it is impossible to remain slaves of sin. Our new nature in Christ guarantees a transformed life. Paul emphasizes the change that ought to be manifest in every believer in Romans 6:3-5.
Do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death? Therefore we have been buried with Him through baptism into death, so that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life. For if we have become united with Him in the likeness of His death, certainly we shall also be in the likeness of His resurrection.
As John explains,
In Christ we are not the same people we were before salvation. “Our old self was crucified with Him, that our body of sin might be done away with, that we should no longer be slaves to sin” (Romans 6:6). . . . Our new life as Christians is not an amended old life but a divinely bestowed new life that is of the same nature as Christ’s very own. . . .
That does not mean our sinful tendencies are annihilated. The Greek word translated “done away with” literally means “to render inoperative, invalidate.” Sin has lost its dominating control over us. Obviously we all struggle with sinful propensities. Death to the sinful self does not mean death to the flesh and its corrupted inclinations. Because of the pleasures of sin and the weakness of our remaining flesh, we often yield to sin.
The tyranny and penalty of sin have been nullified, but sin’s potential for expression has not yet been fully removed. Our human weaknesses and instincts make us capable of succumbing to temptation. . . . We are, in short, new creations—holy and redeemed but wrapped in grave clothes of unredeemed flesh. We are like Lazarus, who came forth from the grave still wrapped from head to foot in his burial garments. 116-117
As slaves of righteousness, our entire being has been rescued and reoriented under the authority of Christ. Through the work of the Spirit, we are being conformed into Christ’s character and refined for the work of His kingdom.
However, we still bear some of the grave clothes of our former nature. Next time we’ll look at another key passage from Paul’s letter to the Romans that describes the believer’s constant battle with sin, and the way sin attacks our assurance of salvation.