Jesus’ first coming was God’s invasion of enemy occupied territory. He landed behind enemy lines to begin the work of setting the captives free (Isaiah 42:7; 49:9; Luke 4:18-21). He provided freedom from bondage by His work on the cross (Luke 13:12; Romans 6:18, 22). He showed the way to have victory through the light that overcame the darkness (John 1:5; 3:19; 8:12). When His mission was completed He ascended to heaven.
However, the fact that He left didn’t mean the war ended. Although defeated and awaiting his ultimate doom, Satan is still free to attack God through His people. Because he knows his end is near he works all the harder to wreak havoc on God’s people and work. God allows Satan freedom to attack because that is part of allowing mankind a free will. Also, God uses Satan’s evil to show mankind their need of Him and for His people to grow in faith as we trust Him and learn to fight.
Now it is Christians who are the ones in enemy-occupied territory. Jesus has called us to be the light of the world. It is up to us to spread His message of deliverance. But the darkness tries to put out our light so none will be attracted to it (John 1:5; 3:19; 8:12). Satan and his demons try to get us back into bondage and misery. It is their entire focus, day and night, and all their skill and energy are focused on bringing this about. We know that God is greater (1 John 4:4) and His kingdom will prevail (Revelation 19-22), but still the battle rages.
So the Christian life is a life of warfare. As the book of Acts shows, that has always been the case. We are at war: war with our sin nature and war with Satan and his forces. That was true for the Christians who were left when Jesus returned to heaven as well. As the early church grew we see the battles continuing. We live in a Satan-controlled world (1 John 5:19). We must fight. God has given us the equipment we need (2 Corinthians 10:4; Ephesians 6:10-20). We can learn how to have victory in our battles by studying the victories, and failures, of those who have gone before. The book of Acts shows examples of those who have already fought their spiritual battles. The writings of Luke, Paul, Peter, John and others help us learn how to apply Jesus’ victory to our own life.
The book of Acts records the growth of the early church. This comes about through evangelism. The Christians are young believers with much to learn, including spiritual warfare. Satan continued to do all he could to stop and destroy the young church before it grew large and strong. There are about 150 references to the spirit world in the Gospels (many of these are from parallel accounts found in more than one gospel) but about 178 additional such references in the rest of the New Testament, so spiritual warfare by no means ended with the ascension. If there is any change in Satan’s tactics between the Gospels and Acts it would be that he attacked Jesus directly and overtly when He was on earth.
However, in Acts we see more deceptive, subtle ways of working to bring about their destruction. That doesn’t make him any less dangerous for us, but actually more dangerous. He works harder to cover his trail and make what he does appear like it is something else (emotional disorder, chemical imbalance, etc.). He attacks more from within instead of just from without. He still uses persecution, but has become adept at dividing families, churches and even nations from within. The battle continues, it just changes a bit. If anything, it is more difficult to fight a subtle, hidden foe than one who is obvious and easily seen.
Spiritual warfare has not decreased. Rather it has increased through the centuries. God tells us it will continue to get worse and worse until Jesus returns. The book of Revelation has the most references to Satan and evil spirits – about 86 references. We know that the nearer to the end times we come, the more active Satan and his forces will be. God has given us His Word to teach us how to live for Him in these days of increased warfare. There is much instruction for us in Acts and the Epistles.
(If I can answer questions or offer personal counsel, or if you would like a free copy of my Spiritual Warfare Handbook, email me at Jerry@ChristianTrainingOrganization.org or download it from http://sw.christiantrainingonline.org/. My next book, Spiritual Warfare in the Bible, which is a more advanced treatment of spiritual warfare, is also available there for free.)