The name “Satan” means “accuser” or “adversary.” What is particularly striking is that here, and throughout the book of Job, his name is spelled with a definite article. His name is “The Satan,” not just “Satan.” The definite article aims to underline his role. He is the accuser, the adversary. What’s he doing? He’s the accuser who has come to accuse. He’s the accuser of the brethren (Rev. 12:10), and as the adversary, he is the prosecuting attorney.
