Inquirer: There are those who maintain that between the Second Coming of the Lord and the end of the world Christ will reign upon the earth, governing, Himself, along with His elect for a thousand years. What is the truth of the matter, Father?
Elder Cleopa: This idea is an ancient one. In the first centuries of Christianity it was endorsed by the so-called Chiliasts or Millenialists. Against them rose the entire ancient Church and its most important representatives.
The divine Fathers of the Church indicated in their writings that the one thousand year reign referred to in the book of Revelation signifies an infinite number of years, i.e. a kingdom that shall have no end. This we know well since from Holy Scripture it is clear that the Kingdom of Christ is not of this world (Jn. 18:36). In Holy Scripture it is clearly indicated that the Kingdom of Heaven is also the Kingdom of God or Kingdom of Christ, in so much as both Saint John the Forerunner and Christ Himself called it so. This Kingdom of Christ will be spiritual and will reign over the internal world of man, while externally being revealed in the righteousness, peace and joy of the Holy Spirit (Rom. 14:17). Christ Himself established this kingdom and explained in His parables how it will appear, who it will include and what power it will possess. His reign will not endure for a thousand years, but eternally (Lk. 1:33). Its inhabitants will include all faithful Christians from all the peoples of the world (Ps. 116:1-2), it will reign over all creation, and it will be a kingdom of righteousness (Dan. 7:13-14). It will be a kingdom made up of souls (Mt. 28:18) — souls that have already entered and lived within it in this present life.