after 1,000 years – after the Kingdom of heaven has been cleansed, and Christ’s prayer for the saints to be united by the truth has been fulfilled! This may be the greatest moment of the Church, and mankind for as Jesus prayed “the world may believe that You sent Me” (John 17:21). This is also a time of peace, when “the mountain of the house of the LORD is established” and the nations will “hammer their swords into plowshares” (Isaiah 2:2-4).
However, as Paul said, “while they are saying: ‘Peace and safety’ then destruction will come upon them suddenly” (1 Thess 5:3). And for those who remain outside the sanctified Church, it will be a very difficult time, as was saw in the 5th bowl of wrath.
released from his prison – the abyss
deceive the nations – this is described in Rev 16:13-14. In the fifth trumpet, we learn that the nations are plagued by demons for 150 years, before they are gathered together at the battle of Armageddon.
Gog and Magog – from Ezekiel 38:1, “Gog in the land of Magog.” Gog is the Ruler, who Daniel called “the King of the North” (Daniel 11:40-45). Magog is one of the children of Japeth, a son of Noah, and is identified by most as one of the European people.
like the sand of the seashore – 200 million men, as per Rev 9:16.
on the broad place of the earth – from Rev 16:16, it seems they will initially gather at Armageddon, which is a high place, and the location of three famous battles.
From here, it seems they will go down into the broad plain, and surround the City of Jerusalem.
and fire came down – this is the conclusion of man’s existence on this earth. God will send fire down to protect his saints in Jerusalem, by this time, according to Paul “all Israel will be saved,” (Romans 11:26) both spiritually and physically.
and the devil was thrown into the lake of fire – the final death.