What is the kingdom of God? If you are looking for a succint, one-word answer it is that the kingdom of God is an administration. The Apostle Paul described the kingdom of God as an administration:
“In all wisdom and insight He made known to us the mystery of His will, according to His kind intention which He purposed in Him with a view to an administration suitable to the fullness of the times, that is, the summing up of all things in Christ, things in the heavens and things upon the earth.”
(Eph. 1:8-10). The Greek word translated as administration is oikonomia, which Thayer defines as “the management, oversight, administration, of others’ property.” Joseph Henry Thayer, A Greek-English Lexicon of the New Testament, (Grand Rapids, MI: Zondervan) 440. Also, included in what is managed by an administration is people. The point is God has set up an administration to manage creation, i.e. people, things and places.
The Apostle Paul states that the administration about which he speaks is designed for the summing up of all things in Christ, i.e. the bringing about, under rulership of the kingdom of God, the reconciliation of all things, not just people, through Jesus. Jesus’ death on the cross opened the door for man’s reconciliation to God, but it did more than that. Paul emphasis the phrase, “all things” by explaining he is speaking things “in the heavens and things upon the earth,” which means the kingdom must be broad enough to administer in the earthly and heavenly realms.
Paul articulated the same concept in his letter to the Colossians saying, “it was the Father’s good pleasure for all the fullness to dwell in Him, and through Him to reconcile all things to Himself, having made peace through the blood of His cross…whether things on earth or things in heaven.” (Col. 1:19-20).
The kingdom of God is broader than heaven and the Church. It is an administration whose earthly borders can in some way bring under its covering non-Christians. More on how that is possible later. GS