There is no future "millennial reign of Christ". When the scripture speaks of the "first resurrection" (Rev. 20:4), it is teaching that the souls who die in Christ will spiritually reign with him. "It is appointed for men to die once, and after that comes judgment."  (Heb 9:27)  "Whoever believes in me, though he die, yet shall he live. And whoever lives and believes in me shall never die." (John 11:26) In God - a day is as a thousand years, and a thousand years is as a day. Only the baptized and redeemed Christians will participate fully in this "first resurrection", which will consist in the fulness of spiritual life with Christ in heaven. Thus, metaphorically, they will reign with him for a thousand years.

"Be therefore always of good courage, knowing that while we are at home in the body, we are absent from the Lord. But, going as we do by faith and not by sight, I say we are actually willing, and want to be absent and exiled from the body, so that we may go to be at home with the Lord." (2 Cor 5:6)

This spiritual life after the death of the body, with Christ in heaven, is the first resurrection! Over these, the second death, of the damnation of the body, (after the resurrection of all the dead - at the last judgment) will have no power.

The good pagans will not enjoy the fulness of heaven, nor will any heathen though he be righteous, reign with Christ in heaven as souls of the saints and martyrs will, until the second resurrection - which is the resurrection of the body at the last judgment.

The final resurrection of all the living and the dead at the last judgment, is the second resurrection. (Rev. 20:5)

This passage has caused much controversy over the centuries. It's literal interpretation was condemned as the "millennial" heresy in the very early days of the Church. The early Church Fathers, who were taught themselves by the apostles, clearly understood that this passage was not to be interpreted literally. Many sects continue to believe in strange and various literal versions of this passage. In reality it is completely allegorical and must be read with grave caution. It is this passage which brought about the "pre-trib" post-trib" and "a-millennial" controversies.  Though the passage is confusing, it makes sense, but only if one does not try to force upon it a literal interpretation. A literal interpretation of this passage is a direct contradiction to the clear teaching of Christ. (See Matt. 25:31)

If one attempts to interpret this passage literally, which is so vague, and so difficult, he negates what Christ taught so clearly about his final coming, the last judgment, and the resurrection of the dead in the Gospels.

See: I Cor. 15:52; John 11:26; Matt. 25:31.

It is a great mistake to equate the "reign of Christ for a thousand years" with the "binding of Satan for a thousand years". Though poetically, they are mentioned in same paragraphs, they essentially have no relationship to one another. The reign of Christ for a thousand years means only that the souls of redeemed Christians will reign with Christ in heaven. The binding of Satan for a thousand years means that his power over the world was bound and restrained for a long period of time - after which he is released. The events to follow Satan's release happen in time on earth - as we live in it right now - until the final end of the world.