8 and will come forth to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together to the war; the number of whom is as the sand of the sea.
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 to battle.
Gog and Magog – from Ezek 38:2, “Gog in the land of Magog.” Gog is the Ruler, who Daniel called “the King of the North” (Dan 11:40-45). Magog is one of the children of Japheth, 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.