Yes, Satan is absolutely evil—and the reason is because he is absolutely opposed to God and everything God wants to do. This is why the Bible says that “Your enemy the devil prowls around like a roaring lion looking for someone to devour” (1 Peter 5:8).
Perhaps you’re thinking of the Apostle Paul’s comment that Satan sometimes seems to be like an angel, apparently promoting good and standing for what is right. But even when Satan appears to be on the side of good, he is only using it as a mask to deceive us and hide his real intentions—which are always evil. Paul wrote, “Satan himself masquerades as an angel of light” (2 Corinthians 11:14).
Never underestimate Satan’s power, and never underestimate his ability to deceive us and make us think he isn’t to be feared. In fact, he even deceives some people into thinking he doesn’t exist! He is not as powerful as God—but he still is a powerful spiritual force who works against God in every way he possibly can. No wonder the Bible commands us to “Put on the full armor of God, so that you can take your stand against the devil’s schemes” (Ephesians 6:11).
The most important truth about the devil, however, is this: he is a defeated foe! Yes, he is still at work—but by Jesus Christ’s death and resurrection, He dealt Satan a fatal blow. Death and Hell and Satan have been defeated, and someday Christ’s victory will be complete. Make sure your faith and trust are in Jesus Christ, both now and for all eternity.