King James Bible
"And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together."
Paul employs Roman adoption law where adopted children received full inheritance rights. Having established believers as God's children through the Spirit (v.14-16), he declares the logical consequence: children are heirs to their father's estate. The inheritance is nothing less than God himself and all his promises. Believers share equal inheritance status with Christ, the natural Son, receiving the same glory, kingdom, and eternal life he possesses. Paul introduces a conditional element—sharing Christ's inheritance requires sharing his path of suffering. This echoes Jesus' teaching that disciples must take up their cross, connecting present hardship to future glory. The purpose of suffering emerges: it leads to co-glorification with Christ. This future glorification is both corporate ('together') and transformative, completing the adoption process when believers receive resurrection bodies.