Why does God bind Satan for a thousand years?
God binds Satan for the thousand years to confine him so he can no longer carry out his work of opposition, and specifically so he should deceive the nations no more until the thousand years are fulfilled. This binding is God's doing, not merely an iron chain, and it restricts Satan during Christ's millennial kingdom rule.
Les explains that Revelation 20 gives the Kingdom a particular time frame: after the Tribulation and Armageddon, when Christ has returned and crushed the armies, the thousand-year Kingdom is introduced. An angel comes down from heaven with the key of the bottomless pit and a great chain. Les qualifies that Satan is a spirit being, so the chain is a chain of God's doing; it shows God will confine him where he can no longer carry out his work of opposition. The angel casts Satan into a special place—not hell, not the lake of fire—shuts him up, and seals him, that he should deceive the nations no more until the thousand years are fulfilled. Les notes that after the thousand years Satan will be released, and he says he will give the reason later. The repeated thousand-year language emphasizes that this Kingdom rule and reign of Christ will be a thousand years.
And I saw an angel come down from heaven, having the key of the bottomless pit and a great chain in his hand.
Is Satan bound with a literal iron chain in Revelation 20?
No. Satan is a spirit being, so he does not necessarily have to be bound with a literal iron chain. Revelation 20 describes a great chain of God's doing, showing that God confines him so he can no longer carry out his work of opposition for 1,000 years.
Why does God bind Satan for a thousand years in Revelation 20?
God binds Satan for a thousand years to confine him so he can no longer carry out his work of opposition and to stop him from deceiving the nations during Christ's thousand-year Kingdom rule. The angel casts him into a pit, shuts him up, and seals him until the thousand years are fulfilled.