Paul tells the Romans that the result of the life, death, and resurrection of Jesus is that those who are in Jesus—i.e., those who trust and believe in Him—also share in His Sonship. Jesus is the Son, and through His death and resurrection, all who trust Him have been adopted into the family. We owe nothing to the flesh and everything to the Spirit who gives us life. The love the Father has for the Son is now poured out on us through the Holy Spirit. (This is another way of thinking about salvation, with trinitarian language—the Son came to bring us back into the love of the Father, and the Father’s desire is to share the love He has for the Son, and the Spirit is the love They share.) How do we know that we are sons and daughters? Because the Spirit tells us so, “bearing witness with our spirit.” In other words, the Spirit helps us know in a way deeper than words that we are beloved children of God. This inner witness of the Spirit is an important part of life in Christ. If you have never felt that you are in Christ, then an important prayer to pray is, “Lord, would you please give me a sense of your presence, would you let me know that I am a child of God?”
And then we get to the heart of the chapter:
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 8:17].
We will inherit what Christ inherits, provided that we walk the way of the cross.
Since the first chapter of Genesis, it has been clear that humanity was created to rule in God’s image over all of creation:
26 Then God said, “Let us make man in our image, after our likeness. And let them have dominion over the fish of the sea and over the birds of the heavens and over the livestock and over all the earth and over every creeping thing that creeps on the earth” [Genesis 1:26].
Humanity was made to reign, but the rebellion in the Garden of Eden made that impossible, because sinful humanity was in no position to rule over creation on God’s behalf. In fact, rather than being a part of God’s life-giving plan, rebellious humanity brought death and destruction to creation. But God never gave up the original plan, and the Bible kept talking about it. Here is Psalm 8, for example, marveling at how the Lord created humanity to reign:
3 When I look at your heavens, the work of your fingers,
the moon and the stars, which you have set in place,
4 what is man that you are mindful of him,
and the son of man that you care for him?
5 Yet you have made him a little lower than the heavenly beings
and crowned him with glory and honor.
6 You have given him dominion over the works of your hands;
you have put all things under his feet,
7 all sheep and oxen,
and also the beasts of the field,
8 the birds of the heavens, and the fish of the sea,
whatever passes along the paths of the seas [Psalm 8:3-8].
On the cross, Jesus drew all the sin of the world into His own flesh, and then He died, carrying sin down with Him. But He was raised again in the power of the Spirit while death and sin stayed dead, and thereby the resurrection defeated death and sin forever. Then Jesus ascended into the heavenly places and sits at the right hand of the Father.
The way of Jesus is a way of suffering that leads to glorification. This is how Paul explains this strange path in his letter to the Philippians:
5 Have this mind among yourselves, which is yours in Christ Jesus, 6 who, though he was in the form of God, did not count equality with God a thing to be grasped 7but emptied himself, by taking the form of a servant, being born in the likeness of men. 8And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross. 9 Therefore God has highly exalted him and bestowed on him the name that is above every name,10 so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, 11 and every tongue confess that Jesus Christ is Lord, to the glory of God the Father [Philippians 2:5-11].
Because Jesus was obedient, even to the point of death, the Father has raised Him to rule.
In Romans 8:17, this is the path that Paul lays out for all who believe. Paul says that all who are in Christ Jesus will reign in the New Creation—just as God originally intended—provided that they walk the way of the cross.
The inheritance of Christ is to rule over all, and those are in Christ share in that inheritance. But first, they have to share in His sufferings.
Glory comes through the Valley of the Shadow of Death.