Question: "If angels and demons can't die, what is the point of their engaging in battle?"
Answer: Popular fiction, such as the novel This Present Darkness by Frank Peretti, often features lurid descriptions of spiritual battles in which demons are dispatched by sword-wielding angels with a slash, a flash, and a puff of smoke. The implication is that the demons “die” somehow when sliced in half by angelic blades. It should go without saying that our theology should be based on what the Bible says, not contemporary novels. The Bible teaches the reality of spiritual battle (Jude 1:9). But the Bible also says that, after the final judgment, demons will be consigned forever to the lake of fire (Matthew 25:41; Revelation 20:10). Since demons (and angels) do not “die” or suffer physical wounds, what is the point of doing spiritual battle?
First, we need to remember that not all battles are “to the death.” The point of angels battling demons is not to kill them but to thwart their plans and further God’s plans. In the Bible, we see that angels do battle with demons in order to deliver divine messages to people (Daniel 10:13) and remove Satan’s hordes from heavenly places (Revelation 12:7–8). Demons can be withstood (James 4:7), tortured by God (Luke 8:28), lose what they possess (Mark 9:25–26), be sent to another place (Matthew 8:32), and be removed to the Abyss (Luke 8:31).
Second, there will be a time when Satan and his demons will experience what the Bible calls “the second death,” which is the lake of fire (Revelation 21:8). We look forward to that day because the demons’ main objective in battle is to counter God’s will in the lives of people everywhere—believers and non-believers alike (1 Peter 5:8). We have many examples in the Bible that God has sent His angels to warn, guide, and protect God’s children. One of the best examples of these roles in Scripture is through the story of Christmas. God used angels to inform Zechariah that he would have a son named John (Luke 1:8–20), to tell Mary that she would bear the Messiah (Luke 1:26–38), to declare Christ’s birth to others (Luke 2:8–13), and to warn Joseph to protect his family from King Herod’s wrath (Matthew 2:13).
God has not seen fit to imprison all demons just yet, but He promises that in the last days they will be thrown, along with Satan, into the lake of fire. There is no escape from this fate, and all demonic spirits will be tormented in eternal isolation from God and His children (Revelation 20:10).
The reality of spiritual warfare affects every believer. It is of utmost importance to recognize this warfare that is taking place and be prepared for it. God has given us all that is necessary to stand firm against the devil’s schemes and has commanded us to put on the full spiritual armor (Ephesians 6:10–18).