The garden was a kingdom that the Lord fashioned by divine fiat in which he would reign in life with his holy people. Within the garden-kingdom of God, Adam, the image bearer of God, was appointed to be the Lord’s royal representative or vice-gerent. Therefore, protological life of covenantal communion with God can be understood more precisely as a kind of royal living or kingdom life. It was Adam sharing in the reign of God as an expression of his solidarity with God and the face-to-face fellowship he enjoyed with him in the reciprocal giving of one’s self to the other.
Van Groningen speaks of this as God bringing humanity into “his royal family.” He continues, “[God endowed] them with the privilege and responsibility to be co-workers with Him in the regal tasks to be carried out in creation.” God does not bestow life by bringing people into his presence to be peasants or slaves, but to sit with him on his throne to share in the glory of his kingdom. This point will prove significant when Paul speaks of believers who will “reign in life through the one man Jesus Christ” (Rom. 5:17).
Adam was a public figure, that is, the royal mediator of the covenant of works and as such through his obedience or disobedience would lead all of humanity in him either to reign in life or to be put in bondage to death. Through his disobedience sin entered into the world and its dominion of death spread over all humanity. The restoration and consummation of life, then, would take place in a second and last Adam, a new royal mediator who would triumph over sin and pass beyond the possibility of death, and in doing so bring his people to reign with him in life over the consummated kingdom of glory forever (Rom. 5:17).
The Heidelberg Catechism expounds the significance of Jesus being called the “Christ,” meaning “Anointed,” in terms of his threefold office of prophet, priest, and king:
He has been ordained by God the Father and has been anointed with the Holy Spirit to be our chief prophet and teacher who perfectly reveals to us the secret counsel and will of God for our deliverance; our only high priest who has set us free by the one sacrifice of his body, and who continually pleads our cause with the Father; and our eternal king who governs us by his Word and Spirit, and who guards us and keeps us in the freedom he has won for us (Q. 31).
We are called “Christians” because we are members of Christ by faith and so share in his threefold anointing, filled with his Spirit of royal glory.
I am anointed [as a prophet] to confess his name, [as a priest] to present myself to him as a living sacrifice of thanks, and [as a king] to strive with a good conscience against sin and the devil in this life, and afterward to reign with Christ over all creation for all eternity (Q. 32).
Or in the words of Paul,
The Spirit himself bears witness with our spirit that we are children of God, and if children, then heirs—heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him (Rom. 8:16-17).
All who believe in the risen Lord Jesus Christ have the shackles of the first Adam broken and the royal promise that God himself will place upon their head the crown of life (James 1:12; Rev. 2:10).
 Adam was not only king, but also prophet and priest in the garden-kingdom.
 Van Groningen, From Creation to Consummation, 1:64; see also T. Desmond Alexander, From Paradise to the Promised Land: An Introduction to the Pentateuch (3rd ed.; Grand Rapids, MI: Baker Academic, 2012), 119-33; idem., From Eden to the New Jerusalem: An Introduction to Biblical Theology (Grand Rapids, MI: Kregel Publications, 2008), 76-79: “to be made in the ‘image of God’ is to be given regal status” (77).