The church as the community of Christ’s kingdom on earth is a theo-political order.
While all things are under the rule of Christ, it is his saving rule that constitutes his kingdom (Col. 1:13).
The church is the heavenly polis on earth, the new humanity whose hearts have been circumcised by the Holy Spirit. Its breadth reaches out to all peoples; its depth renews the heart (Jer. 32:39; Ezek. 11:19).
We have no abiding city here; the church cannot be identified with the kingdoms of this world (Heb. 13:14).
But we do have a city with foundations, whose builder and maker is God. As such, the church exercises heavenly citizenship in the fellowship of the saints (Heb. 11:10, 16; 12:28; Phil. 3:20).
The community exists on earth, but is governed by the keys of the heavenly kingdom, with spiritual, not physical sanctions (Matt. 16:19; Rev. 3:7).
—Edmund P. Clowney, The Church, Contours of Christian Theology (Downers Grove: IVP, 1995), 189.