That man could once again be in God's family. Man could only become a child of God by receiving the nature of God. We could say that Christ came that we, that man, might receive Eternal Life. Man could receive Eternal Life only after he had been legally redeemed from Satan's authority. It is related to something we will call Identification.
Identification is two-fold.
Man's identification first of all with Adam. And then man's identification with Christ. The entire plan of redemption revolves around this two-fold identification of man with Adam and with Christ. Paul was given the revelation of our redemption and the present ministry of Christ. Paul's revelation was man's identification with Adam and with Christ.