"Several expressions Paul uses help to illuminate the wonder of Christ's grace. They suggest, as it might be put, that Jesus is portrayed here as 'Adam in reverse' (cf. Rom. 5:12-21).

(i) His being in the form of God but not counting equality with God a thing to be grasped (v. 6) reminds us of Adams failure. He was created as the image and likeness of God (Gen. 1:26). But he grasped after equality with God ('you will be like God' [Gen. 3:5], the tempter suggested). By contrast, Jesus, whose right equality with God always was, did not refuse to become obedient (v. 8).

(ii) The Son made himself nothing [emptied himself] ... taking the form of a servant (v. 7). Here we may have an echo of the great prophecy in Isaiah 52:13-43:12, where the Sufferer 'poured out his life to death' (Isa. 53:12). He is described by God as 'my servant' (Isa. 52:13). He did what Adam refused to do: serve God.

(iii) The incarnate Son became obedient to the point of death. In Romans 5:12-21 Paul gives us an exposition of these words by means of an extended comparison between Jesus and Adam. Adam's disobedience brought sin and death into the world; by contrast, Jesus' obedience brings righteousness and life into it."
— Sinclair B. Ferguson (Let's Study Philippians)