20 Then I saw an angel coming down from heaven, holding in his hand the key to the bottomless pit and a great chain. 2 And he seized the dragon, that ancient serpent, who is the devil and Satan, and bound him for a thousand years, 3 and threw him into the pit, and shut it and sealed it over him, so that he might not deceive the nations any longer, until the thousand years were ended. After that he must be released for a little while.
4 Then I saw thrones, and seated on them were those to whom the authority to judge was committed. Also I saw the souls of those who had been beheaded for the testimony of Jesus and for the word of God, and those who had not worshipped the beast or its image and had not received its mark on their foreheads or their hands. They came to life and reigned with Christ for a thousand years. 5 The rest of the dead did not come to life until the thousand years were ended. This is the first resurrection.
The parallel nature of the successive visions in Revelation seems also to substantiate this interpretation of the binding of Satan. In 12:5ff, (also the beginning of a section) we read that 'the great dragon was cast out' - this in association with Christ's atoning work and ascension and coronation, when He was 'caught up unto God and to His throne' (12:5). The identity of reference is surely unmistakable and incontrovertible. This means, however, that the thousand years cannot refer to a literal period of time, but are symbolic of the entire age between the first and second comings of Christ. But why should we take them as literal? The seven churches in chapters 2 and 3 do not mean that there were only seven churches in Asia (Acts can name others); the seven-horned, ten-headed monsters were not to be taken literally, nor were the 144,000. Why should the thousand years be an exception? The reign of Christ is spoken of as lasting a thousand years, because it is the symbol of completion and fulfilment, - of new time that has broken in, of the perfect life of eternity that has entered into time. In harmony with this idea is the apostolic assertion in the early Church, 'Jesus is Lord'. In a very real sense they recognised that with His atonement and victory Christ's reign had begun already, and what we have here is a pictorial representation of what to them was a basic, glorious reality. To them Satan was a defeated foe, and Jesus Christ, the Lord, had defeated him. It was this that John was being reminded of in the vision, in spite of all that in his circumstances at the time might seem to contradict it.