The book "War and Peace" by Russian Leo Tolstoy is considered one of the greatest books of all time. However, the world misunderstands the nature of war and peace from a spiritual perspective. Men and nations have fought wars for millenia, but they are no closer to any solutions to the problems of life now than they were thousands of years ago. That is because man fails to understand that the natural world at best is only symbolic and symptomatic of what is going on in the spiritual world. Most people do not even attempt to pay attention to where the real war is taking place, have a proper understanding of what is going on, know what to do about it, get properly equipped to engage it, and get into the arena and do something about it. Sadly, this is also true of many Christians.
The real war is taking place in the invisible but very real spiritual world. It started when Satan rebelled against God. Some of the angels decided to join him in his attempted coup, and were cast out of heaven to earth (Luke 10:18, Hebrews 2:2, 2Peter 2:4, Jude 6, Revelation 12). How sad it is to think of war in heaven. Yet the war did not end yet. It only changed arenas. The name Satan means adversary. He is the enemy of God, but not His equal. God has no equal (Isaiah 40:25, Isaiah 46:5). the devil cannot conquer God, so he does what he can - he deceives man who is made in the image of God. He cannot force man to do anything. He could not even stop a man possessed with 6,000 demons from running to the feet of Jesus, worshiping Him, being delivered, and being a witness to ten cities (Mark 5:1-17). What he does is mess with people's thinking about God, sin, and themselves so they make the wrong choices. That is why we need to know the Bible.
Wars in the physical world happen because of the sinful nature of man (James 4:1-4). Wars in the spiritual world happen because the devil is trying get people whom he cannot destroy directly to destroy themselves. God equips His people with all the things they need to fight and win this war (Ephesians 6:10-18). The great warriors in the Bible such as Joshua and David understood that the only way they could be victorious was to pray and follow the word and direction of God (Joshua 1:1-9, 1Samuel 23:2-4, 1Samuel 30:8, 2Samuel 5:19-23). In 1Samuel 25, David was going to fight a battle to avenge himself, but was wisely advised against it. Abigial reminded him that he was only to fight the battles God chose for him. Soon after, David's enemy died on his own. God fought this battle for him.
Peace is also different than what man thinks it is. Most people think peace is circumstantial. When everything is going well, then we can be at peace. News flash - we live in an imperfect world where things don't always go well. If we are going to wait for our circumstances to be perfect to find peace, we will have a long wait. If we are thinking that someday in this world men will stop fighting wars, we are naive at best. Peace is not a state of affairs, it is a state of mind. The Lord Jesus burst the bubble on circumstantial peace. "Think not that I am come to send peace on earth: I came not to send peace, but a sword (Matthew 10:34)." "These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world (John 16:33)." He even told His disciples they would die for Him (Matthew 24:9), but they could still have peace. The Lord does not desire evil in the world, but He knows that man will never find circumstantial nor inner peace in sin (Isaiah 48:22, Isaiah 57:21, Jeremiah 6:14, Jeremiah 8:11, Ezekiel 13:10-16, 1Thessalonians 5:3).
Peace is not the absence of outer conflict. It is the inner victory over sin through Jesus Christ. The only peace we will find in this world is in a true relationship with God. When our relationship with God is according to His word, circumstances can come and go, but we can have peace knowing our eternal soul is in His hands. Someday the Lord will return and rule the world. Only then will there be real circumstantial peace (Revelation 19-20). In the meantime, we can enjoy the inner peace only God can give us (Philippians 4:17, Colossians 3:15). It is not just peace from God. It is His peace in us, because He is in us. "Peace I leave with you, my peace I give unto you: not as the world giveth, give I unto you. Let not your heart be troubled, neither let it be afraid (John 14:27)."