John saw an angel descending from heaven. This angel had the key of the abyss and a great chain in his hand (literally, “upon his hand,” suggesting that the chain was ready for use). The need for a great chain could indicate that the dragon possessed tremendous strength and was fierce. (Compare Mark 5:2-4.) Earlier, the Son of God had identified himself as having the keys of death and of Hades. (1:18) The fact that the angel was seen with the key of the abyss, however, would not require that he be identified as a figure of the Son of God. The angel would simply be the agent for carrying out Christ’s purpose and, ultimately, that of his Father respecting the dragon and, therefore, would need the key of the abyss. John identified the personage as an angel, and there is no contextual reason for adopting a different meaning. (20:1)
The angel seized the dragon, the “old serpent” (recalling the use of the serpent to deceive Eve), the Devil (slanderer of God) and Satan (the resister or opposer of God), and bound him for 1,000 years. He then cast the bound dragon into the abyss, thereafter locking and sealing it shut to prevent the dragon from misleading the nations. At the end of the period of confinement, the dragon would be released for a short time. (20:2, 3)
The period of 1,000 years may simply be descriptive of a long time, as the numbers in the book of Revelation are symbols. Subsequent to the banishing of the powers of darkness, with no possibility of breaking free, the nations (apparently the people from all nations who are not among those perishing because of defiantly fighting against the Son of God) would enjoy a long time under Christ’s beneficent rule and without any satanic influence.