Well, that’s what God’s Word says.
The Great Commission was Christ’s words to His true followers (true disciples: “Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit, teaching them to observe all that I commanded you; and lo, I am with you always, even to the end of the age.” [Matthew 28:19-20]
All authority was given to Him by the Father, our Creator, in heaven and on earth.
The Great Commission was about proclaiming the gospel of salvation through Jesus Christ, telling people to repent of their sins so that they might be forgiven of them through faith in God’s only begotten (unique) Son, whom He provided as a perfect and sinless sacrifice on our behalf. God raised Him from the dead as He promised, so that all who believe in Him might also be raised up to walk in newness of life here on earth and later when He returns. It’s about a relationship with the living God through His living and beloved Son, not about a theocracy on earth.
His enemies will be made a footstool for His feet at the end of the 1000 year reign. The 1000 year reign is a theocracy; Jesus will usher in a reign of justice and righteousness on the earth and rule over the people of the earth.
The timing of His enemies being made His footstool is found in 1 Corinthians 15:23-26, in the context of the order of events of the First Resurrection (v. 20-28.
The order of the First Resurrection is:
1. Christ the first fruits, v. 23
2. Those who are Christ’s at His coming, v. 23
First Coming: Matthew 27:50-53; Second Coming: Rev., Dan., 1 Thess.
a. the Church (1 Thess. 4:13-18)
b. the 70th Week saints (Rev. 20:4)
c. the O.T. saints (Dan. 12:1-2)
d. the righteous Jews whom He gathers when He comes
(Matthew 24:31)
3. He reigns until all His enemies are under His feet, v. 25; the last enemy that will be abolished is death, v. 26.
4. Then the end when He delivers up the kingdom to the Father, v. 27-28.
The purpose of the Millennium (the 1000 Year Reign of Christ on this earth) is given in v. 25—to put all His enemies under His feet.
That’s all post-Reformation heretical innovation.
For roughly 1,700 years that doctrine did not exist.
I would study the attainments of the Reformation honestly and at great length before I disagreed with them on eschatalogy, or even any other doctrinal subject, IMHO.
Being an American, the “Pilgrims” that came to America in 1620 are always a valuable group of Christians to study.
You’ll find no Christmas, no Easter, etc.
Which was what the Protestant Reformation was all about - reforming the Church to rid it of grave errors of doctrine and practice, and restoring Church doctrine to what it is expressed as in the Word of God.
It’s such a shame that we ignore those attainments, when so many people were martyred in achieving them.