From the earliest times following the generation of Jesus & His Apostles, many, many Christians have regarded the dead in Christ as having become very much alive and exalted to positions of authority over the Church and the World, having supplanted the former principalities & powers of Ephesians 6:12. Such doctrines are a tacit witness to the position of global, historic Christianity that some form of the First Resurrection occurred around the time of the disappearrance of the Apostles. even though the Resurrection of the Rest of the Dead yet remained future, at the end of the Millennium in which they saw themselves living. Around the time of the Council of Nicea in 325AD, such beliefs came into full bloom throughout global, historic Christianity and are strongly held throughout the bulk of Christianity even today: (Roman Catholicism, Eastern Orthodox, Russian Orthodox, Anglican, etc.) It is partly what is meant in the Apostles' Creed,"I believe ... in the communion of the Saints." This accords well with the 56AD predictions of Christ's persecuted Apostle Paul and with what Christ's exiled Apostle John had foreseen around 63AD in the predictive vision of the book of Revelation. It was all expected to shortly come to pass after the New Testament was written.
1 Corinthians 6:2-4 ~written around 56AD by Christ's persecuted Apostle Paul to the Church at Corinth
Do you not know that the saints will judge the world? And if the world will be judged by you, are you unworthy to judge the smallest matters? 3 Do you not know that we shall judge angels? How much more, things that pertain to this life?
Revelation 20:4-6 ~foreseen around 63AD in the predictive vision to Christ's exiled Apostle John about "those things shortly to come to pass," Rev 1:1 & Rev 4:1
4 And I foresaw thrones, and they sat on them, and judgment was committed to them. Then I foresaw the souls of those who had been beheaded for their witness to Jesus and for the word of God, who had not worshiped the beast or his image, and had not received his mark on their foreheads or on their hands. And they lived and reigned with Christ for a thousand years. 5 But the rest of the dead did not live again until the thousand years were finished. This is the first resurrection. 6 Blessed and holy is he who has part in the first resurrection. Over such the second death has no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.