The last Adam is Jesus Christ, the risen and obedient head of the new humanity who fulfills what Adam abandoned and gives resurrection life to those united to Him.
Where the first Adam grasped, Christ humbled Himself and obeyed. Entering Adam’s mortal world as true man, He bore God’s image perfectly, lived in faithful dependence upon the Father, and passed through death into resurrection life over which death has no dominion.
He is not Adam merely repaired but the beginning of a new humanity. What Adam received and corrupted, Christ fulfills; what Adam brought under death, Christ carries through death into life; and He gives that risen life to all whom the Spirit joins to Him. He has already received all authority, yet awaits the day when His reign is made visible and every enemy is placed beneath His feet.
See in Scripture: Romans 5:12–21; 1 Corinthians 15:20–28, 45–49; Philippians 2:5–11; Hebrews 2:5–18