¹² So then, brothers, we are debtors, not to the flesh, to live according to the flesh. ¹³ For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live. ¹⁴ For all who are led by the Spirit of God are sons of God. ¹⁵ For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!” ¹⁶ The Spirit himself bears witness with our spirit that we are children of God, ¹⁷ and if children, then heirs—heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him. – Romans 8:12-17 ESV

If you are a child of God, you owe Him, not that you could ever pay Him back for what He has done for you, but you should live with a deep and lasting awareness of your indebtedness to Him. He sacrificed His Son on the cross so that you might have life.

For you know that God paid a ransom to save you from the empty life you inherited from your ancestors. And the ransom he paid was not mere gold or silver. It was the precious blood of Christ, the sinless, spotless Lamb of God. – 1 Peter 1:18-19 NLT

Those of us who are in Christ owe God our lives, literally. Our debt to sin was paid in full on the cross. God’s righteous judgment was satisfied by the death of His own sinless Son. As a result, we are free to reject the demands of our sinful flesh. We can say no to the sin-stained desires that constantly tempt us to rebel against the will of God, but only with the help of the indwelling Holy Spirit. Paul makes it clear that it is “by the Spirit you put to death the deeds of the body” (Romans 8:13 ESV).

The Spirit is the one who gives us the strength to live righteously, even though our sinful natures are alive and well within us. We are now sons and daughters of God who have the Spirit of God living inside of us. While this new reality is difficult for us to comprehend, it is essential for us to believe by faith, because it is the key to our victory over sin in this life.

Jesus died to pay for our sins, and the Spirit lives within us to give us power over sin. Sin can no longer condemn us, but it can distract and defeat us. Which is why Paul emphatically states that we are no longer on our own when it comes to dealing with sin. We are sons and daughters of God, and we are led by the Spirit of God. And the very fact that we have the Spirit within us, convicting, encouraging, and guiding us, is proof of our new relationship with God.

The Spirit himself bears witness with our spirit that we are children of God. – Romans 8:16 ESV

When we experience conviction over sin, that is the Spirit at work within us. When we read the Word of God and hear Him speak to us, that is the result of the indwelling Spirit of God. Any time we find ourselves exhibiting love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control, that is the fruit of the Spirit in our lives, and that fruit reveals that we belong to God. We are His children, adopted into His family and rightful heirs to all that belongs to Him. And while that may be hard for us to grasp, it is vitally important if we are ever going to experience the kind of abundant life that Jesus promised us.

Paul wants us to think about our future inheritance, rather than dwell on the temporary pleasures that our sinful flesh tends to obsess over. We are heirs of God, and He has something incredible in store for us that is not of this world. The apostle Peter found the very thought of it worthy of praise to God.

All praise to God, the Father of our Lord Jesus Christ. It is by his great mercy that we have been born again, because God raised Jesus Christ from the dead. Now we live with great expectation, and we have a priceless inheritance—an inheritance that is kept in heaven for you, pure and undefiled, beyond the reach of change and decay. – 1 Peter 1:3-4 NLT

But there is another aspect to our inheritance. As fellow heirs with Christ, we share in the reality of our future glorification. Just as He received a new glorified body and was reunited with His Father in heaven, so will we. But during this life, we also share in His suffering. As the Son of God, He suffered on this earth. He was ridiculed and rejected by men. He was misunderstood and falsely accused. His message of salvation was dismissed, and His claims of deity were denied. Ultimately, He suffered a humiliating and excruciating death on the cross. So as children of God, we are “heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him” (Romans 8:17 ESV).

We experience suffering in this life because we are not of this world; we no longer belong here. In fact, Paul emphasized to the believers in Colossae that their faith in Christ transferred their citizenship from earth to heaven.

He has enabled you to share in the inheritance that belongs to his people, who live in the light. For he has rescued us from the kingdom of darkness and transferred us into the Kingdom of his dear Son, who purchased our freedom and forgave our sins. – Colossians 1:12-14 NLT

Peter referred to Christ-followers as “temporary residents and foreigners” and urged them to “keep away from worldly desires that wage war against your very souls” (1 Peter 2:11 NLT). Our new identity and status as sons and daughters of God put us at odds with this world and the prince of this world. As believers, we face a triad of opposition to our newfound status as citizens of heaven: The world, the flesh, and the devil.

For the world offers only a craving for physical pleasure, a craving for everything we see, and pride in our achievements and possessions. These are not from the Father, but are from this world. – 1 John 2:16 NLT

Once you were dead because of your disobedience and your many sins. You used to live in sin, just like the rest of the world, obeying the devil—the commander of the powers in the unseen world. He is the spirit at work in the hearts of those who refuse to obey God. All of us used to live that way, following the passionate desires and inclinations of our sinful nature. By our very nature we were subject to God’s anger, just like everyone else. – Ephesians 2:1-3 NLT

Stay alert! Watch out for your great enemy, the devil. He prowls around like a roaring lion, looking for someone to devour. Stand firm against him, and be strong in your faith. – 1 Peter 5:8-9 NLT

“The world would love you as one of its own if you belonged to it, but you are no longer part of the world. I chose you to come out of the world, so it hates you.” – John 15:19 NLT

Jesus warned us that the world would hate us because it hated Him. And His words have proven painfully true. This world is not our friend, and the more we live out our new identity as children of God, the more animosity we will experience from this world. Just prior to His death, Jesus told His disciples, “I have told you all this so that you may have peace in me. Here on earth you will have many trials and sorrows. But take heart, because I have overcome the world” (John 16:33 NLT).

And Paul will close out this chapter with his own words of encouragement.

No, despite all these things, overwhelming victory is ours through Christ, who loved us. And I am convinced that nothing can ever separate us from God’s love. Neither death nor life, neither angels nor demons, neither our fears for today nor our worries about tomorrow—not even the powers of hell can separate us from God’s love. – Romans 8:37-38 ESV