Romans 8:23

The saints share the sense of groaning and anticipation that Paul described the whole creation feeling. God will fully redeem both it and us finally. However only the saints have the firstfruits of the Spirit.

God commanded the Israelites to present a portion of their harvest that ripened first as an offering to Him (Exodus 23:19; Nehemiah 10:35). This offering acknowledged that the whole harvest was from Him and was really His. It was an offering that the Israelites made in faith, confident that the rest of the harvest would follow.

Similarly God’s gift of the Spirit at the commencement of the believer’s Christian life is His pledge that He will complete the process of salvation. Even though He has redeemed and adopted us, there is more of redemption and adoption for us to experience in the future (Ephesians 1:13-14; Ephesians 4:30; 1 John 3:2). When will that take place? It will happen at the Rapture, when He glorifies our bodies by making them immortal (Philippians 3:20-21; cf. 1 Corinthians 15:44; John 14:1-2). The judgment seat of Christ will follow, when we will receive more of our glorious inheritance (1 Peter 1:3-4; 1 Corinthians 3:12-15; 2 Corinthians 5:10).

"The ’adoption’ here is the full manifestation of the status of believers when they are invested as sons and daughters of God (cf. Romans 8:14-17) and enter on the inheritance which is theirs by virtue of that status. ’The redemption of our bodies’ is the resurrection, a theme on which Paul had recently enlarged in 2 Corinthians 4:7 to 2 Corinthians 5:10." [Note: Bruce, pp. 164-65.]