Then I saw an angel coming down from heaven, holding in his hand the key to the bottomless pit and a great chain. And he seized the dragon, that ancient serpent, who is the devil and Satan, and bound him for a thousand years, 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. (Revelation 20:1-3 ESV)
If you are an amillennialist or a postmillennialist, this verse poses a little problem. How can it be that Satan is bound, and yet he also “prowls around like a roaring lion, seeking someone to devour” (1 Pet. 5:8)?
The answer is that, especially for a spiritual being like Satan, binding may refer to something other than total physical restraint. In Satan’s case, it refers to a sort of covenantal or legal restriction placed upon Satan by God. He is not allowed to “deceive the nations” while the church undertakes to disciple the nations, but he may still “prowl around.”
Consider Romans 7:2, which uses the same word but in this legal or covenantal sense:
For a married woman is bound by law to her husband while he lives, but if her husband dies she is released from the law of marriage.
In this sense, it is proper to speak of ourselves as bound to God, and even to speak of God as bound to us. Calvin writes of God’s “mutually bind[ing] himself to us without having to do so.”