Answer
The Bible explicitly informs us of the existence of Satan. He is described as the enemy of man (Genesis 3:15), the father of lies (John 8:44b), and the accuser (Revelation 12:10), among other things. The very name “Satan” means “adversary.” Isaiah 14:12–17 explains that Satan was originally an angelic being, but he decided he wanted the honor and worship due only to God and was thrown out of heaven (also see Ezekiel 28:11–17).
Ever since he was cast out of heaven (along with the angels who chose to rebel with him), Satan has made it his purpose to oppose God and lead the people of earth into rebellion as well. Satan has a certain authority in this world; he is called “the god of this age” (2 Corinthians 4:4) and “the prince of the power of the air” (Ephesians 2:2). That’s why we are to “be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour” (1 Peter 5:8).
One big way Satan wreaks havoc in our lives is through deception. When Satan deceives us about who God is, who God says we are, and who he is, he gains power and authority in our lives. “Satan does not exist” is one of the most potent lies Satan tells.
At creation, God gave mankind authority over the earth (Genesis 1:28). When Adam and Eve willingly disobeyed God, they gave up some of their authority; in listening to Satan, they subjugated themselves to the devil. Yet, at the cross, Jesus stripped Satan of his authority: “Now is the time for judgment on this world; now the prince of this world will be driven out” (John 12:31). “The reason the Son of God appeared was to destroy the devil’s work” (1 John 3:8). Satan has no more authority over those who are in Christ, except when they give it to him by believing his lies.
Much misinformation about Satan comes from Hollywood and other flawed sources. It’s imperative that we go to the Bible for the truth on this and other matters. The Bible plainly tells us that Satan does exist, and it cues us into how he operates. We have no reason to be intimidated by Satan, as his power is infinitely inferior to God’s, but the Bible teaches us not to be naïve in our spiritual battle (Ephesians 6:10–18). The key is to submit to God and resist the devil (James 4:7), knowing that Christ has defeated him for good at the cross and Satan’s end—eternal judgment—is assured (Revelation 19:20).