Putting sin to death, likewise, is a difficult duty for the Christian, but Paul teaches us that it is necessary and possible. Romans 8:12–13 states that life in the Spirit includes liberation and mortification. We are no longer debtors to this present, evil age, so we walk in a different direction, think after the realm of Christ, and relate to God in a covenant of grace. Since God has delivered us, we are indebted and enabled to walk according to the Spirit, and we express our indebtedness by putting sin to death in the power of the Spirit.
Squatters are notoriously difficult to evict. They may disappear for a while, making you think they are gone, yet they always find a way back and may even bring a few friends along. Indwelling sin is not so easy to evict either, but it is a necessary duty of the Christian life. We are Christ’s temple, therefore all squatters must go. In Romans 8:12–13, Paul teaches us that mortification is not only necessary but possible. Putting sin to death is necessary because Christ has delivered us from this sinful age and possible because the Spirit of Christ leads us in holiness. This means that we are no longer debtors to live according to the flesh; rather, we are indebted and enabled to live according to the Spirit.
No Longer Debtors
Paul concludes the first eleven verses with a negative implication: “So then, brothers, we are debtors, not to the flesh, to live according to the flesh” (Rom 8:12). You are no longer a debtor to the powers of this present, evil age because the Spirit of life has set you free from the condemnation of the moral law (v. 1) and the law of sin and death (v. 2). When the Holy Spirit takes up residence in your heart, he changes the direction of your life, the object of your mind, and your covenant with God.
Prior to regeneration, you were a debtor to the flesh. You walked according to the flesh (v. 4), set your mind on the things of the flesh (v. 5), and lived at enmity with God (v. 7). Outside of Christ you were spiritually dead, but you were by no means static or lifeless. To the contrary, you walked in the same direction as the world and followed the powers of this present age (Eph 2:1–2). Like those floating down the lazy river in an amusement park, so you were floating along in the same direction as this rebellious age. Furthermore, you set your mind on the things of the flesh. Your thinking was restricted to this sinful age, not the spiritual age of Christ. This means that you gave little thought to the divine, heavenly realm, to Christ and his gospel, or to God and his Word. Perhaps you did think about heaven–a life of eternal bliss and freedom from pain–but you did not think about Christ, your Savior and Lord. You were captivated and lured by the sins of the age. Finally, verse 7 teaches that you not only walked with the world, thought with the world, but you were at enmity with God. Before the Spirit of life united you to Christ you were in Adam, your federal head, and related to God through a broken covenant of works.
Now that you are indwelt by the Spirit of life, you are no longer a debtor to this age. You do not have to live for the flesh. This is the emphasis of Paul’s “therefore” in verse 12. Since you are united to Christ and indwelt by the Spirit, you are no longer a debtor to this world; rather, you are a son of God and heir with Christ (v. 15–17). When the world demands your allegiance or worship, you are free to refuse because you belong to another master. You were delivered from this world and bought by the Son. While we live in this world, we do not live for this world. We walk in this world, but we do not walk in sync with this world. Since we are sons of God, and no longer debtors to this age, we walk upstream in a downstream world, set our minds on the permanent age of the future, not the transient age of the present, and relate to God in a fulfilled covenant of grace, not a broken covenant of works.
Now, Paul is not just saying you do not have to live according to the flesh. In verse 13, he emphasizes that you ought not to do so. The transition from v. 12 to v. 13 is a shift from deliverance to warning. In verse 12, Paul emphasizes that you do not have to live for this world because you have been delivered from its grip. In verse 13, Paul shifts to a warning, saying that you ought not to live according to the flesh because those who do will surely die.
Verse 13 “If you live according to the flesh, you will die.” The first thing to note about this conditional warning is what it is not saying. It is not saying that those who have been delivered from this present age can lose their salvation. Rather this is a warning to the unrepentant, those who hold Christ in one hand and their sin in the other. Death is the eternal punishment for those who willfully persist in unrepentant sin, who obstinately refuse to part with their beloved sins, and who claim God as their Savior but deny him as their Lord. Death is the just punishment for those who walk according to the flesh, set their minds on the things of the flesh, and live according to the flesh.