“The current reign of Christians in this world is the most subversive truth on earth.”
I think you are misreading the the intent of the passage; it is referring to our regeneration; our union with Christ, not reigning. It is not realized eschatology, but a reference to our future inheritance as in Eph. 1:13-14, “In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that Holy Spirit of promise, which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.”.
The Spirit is the present guarantee of the future inheritance, sealing the believer against the coming day of redemption. (Eph. 4:30, “And grieve not the Holy Spirit of God, whereby ye are sealed unto the day of redemption.”) That God has already seated His people with Christ in the heavenly realm is best understood as a statement of God’s purpose which is so sure of fulfillment that it can be spoken of as having already taken place i.e. Romans 8:30, “Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified”. We have been justified but our glorification has yet to take place although God sees it as done. It’s our experience catching up to our election.
The phrase “in Christ Jesus”, I think, clarifies the meaning. Enthronement with Christ in the heavenly realm is not yet part of the experience of the believer. So far as the believer’s experience is concerned, being glorified lies in the future (Romans 8:17, “And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together”). But the heavenly realm is the believer’s proper location because we are united with Him. Our true home is where Christ is because that is where the believer’s citizenship is (Phil. 3:20, “For our conversation is in heaven; from whence also we look for the Saviour, the Lord Jesus Christ:”). But the community to which we belong to now is the church; heavenly in origin, character, and destiny, but militant here in earth.
The idea of “made us sit together” probably refers more to reclining at a meal as a guest as opposed to being a servant or reigning or ruling since there is no mention of thrones or places of power i.e. Luke 13:29, “And they shall come from the east, and from the west, and from the north, and from the south, and shall sit down in the kingdom of God.”
I agree our glorification occurs in the future and is accomplished by the past work of Christ.
However, it's only logical that men's sanctification itself has a beneficial effect on the earth itself -- the more God's grace shows itself throughout the world by the increasing number of Christians, the better off the world is.
I don't believe the Gospel is defeated in this life. I believe Christ overcomes the world, "on earth as it is in heaven."
It wasn't Paul or Peter who gave the Great Commission; it was Jesus Christ. Did He task us with failure or success?
Looking back at history, it seems as if the pacifism and withdrawal of the Anabaptists has carried over to a lot of today's eschatology. Calvin certainly believed that a growing and vigorous Christianity would positively influence the planet.
To believe the world is going to get worse and worse is to snatch defeat from the jaws of victory.
Cui bono?
Amen.