What does the Bible say about the nature of Satan?

Satan is depicted in Scripture as a powerful, fallen angel who opposes God and humanity. He is referred to as Lucifer ('son of the morning') before his fall, and after his rebellion, he is categorized as a deceiver and the accuser of the brethren (Revelation 12:10). His influence is subtle, often operating behind the scenes to sow doubt, discord, and disbelief among God’s people. He seeks to sift believers as wheat, as mentioned in Luke 22:31, showing his desire to undermine faith. Scripture describes him as the 'prince of the power of the air' in Ephesians 2:2, indicating his authority over the unredeemed and his active role in leading them away from the truth of the Gospel.