Question: "What does it mean that creation waits in eager expectation (Romans 8:19)?"
Answer: In Romans 8 Paul instructs believers about the new relationship we have with God when we believe in Jesus. That relationship impacts not just the individual but, eventually, all of creation: “For the creation waits in eager expectation for the children of God to be revealed” (Romans 8:19).
The revealing of the sons of God that creation awaits has to do with glorification. Paul explains that believers are free from condemnation and from the law of sin and death (Romans 8:1–2). Believers are now living in accordance with the Spirit; they are in the Spirit, and the Spirit of Christ is in believers (Romans 8:5, 9). Believers are adopted as children of God and can call God their Father (Romans 8:15–16). As children of God, believers are also fellow heirs with Christ because they have suffered with Christ (through His death on the cross, see Colossians 3:3–4, and Philippians 3:10, for example). If we have suffered, died, and been raised with Christ, then we will be glorified with Christ (Romans 8:17).
Believers have an incredibly rich new relationship with God the Father, the Son, and the Holy Spirit. All the sufferings and challenges believers encounter in the present time cannot compare with the glory that will be revealed to believers in the future (Romans 8:18). Elsewhere, Paul explains that, when Christ is revealed in the future, believers will be revealed with Him in glory (Colossians 3:4). Not only do individual believers await the glory that is in store, but the rest of creation is waiting, too. All that God made longs anxiously for that glory to be revealed.
At the fall of humanity, the earth was cursed for Adam’s sake (Genesis 3:17–19). Because of the fall, God subjected the earth to futility and to a curse (Romans 5:20; Genesis 5:29). He did this with the anticipation that one day the creation would be set free from its slavery and corruption and would enjoy the freedom of the glory of the children of God (Romans 8:21). In the meantime, however, creation is waiting for the revealing of the sons of God (Romans 8:19). “The whole creation groans” and suffers as if preparing to give birth (Romans 8:22, NASB). The pains are severe, but, just as with childbirth, when the baby is born, there is joy and the labor pains come to an end.
Believers likewise groan with pain under the effects of sin in this world. We are waiting for our birthright as adopted children of God: the redemption of the body (Romans 8:23). While we can’t see now the outward evidence of this adoption and future glory because of the curse in and around us (Romans 8:24), we have been saved and have hope of that future physical redemption (Romans 8:25).
Because believers have the hope of a blessed physical reality, we can endure with perseverance as we eagerly look forward to being glorified with Christ (Romans 8:26). Creation is waiting for the revealing of the sons of God because that is when the natural world will be restored and the curse lifted (Revelation 22:3). The difficulties and struggles of today are not comparable to what God has designed for our future. We look forward to the hope of righteousness (Galatians 5:5). As children of God and heirs with Christ, we look forward to being revealed with Christ in glory.
Because our hope is focused on Christ and His revealing, believers ought to set their mind on things above where Christ is (Colossians 3:4). Because our citizenship is with Him (Colossians 1:13) and our lives are hidden in Him (Colossians 3:3), our identity and existence are no longer defined by the things of earth. Right now, we cannot imagine the glorified state, but all creation is waiting for the revealing of the sons of God. “Dear friends, now we are children of God, and what we will be has not yet been made known. But we know that when Christ appears, we shall be like him, for we shall see him as he is” (1 John 3:2). We have a new relationship with God and a new identity. We are no longer defined by condemnation, curse, and futility.