The verses above from James in the New Testament very clearly explain in easy to understand words why mankind has strife and war. Whether it be individual desiring something that belongs to their neighbor, or a nation seeking to expand it's territorial ambitions, if left unbridled war will be the result. God gives us the capability to defeat those urges by living as He expects, but since we are mortal sinners, conflict will never cease on this earth until man changes his ways. Make no mistake about it, an evil spirit, the one we call the Fallen Angel or Satan, is alive and well in the airwaves of the world and he seeks converts for his way until the time comes when he is banished for eternity.
No place is it better described than in the book of 1 Samuel in the Old Testament. In the years before and including the reign of King David, Israel and the Philistines were constantly at arms with each other. And neither had the upper hand for long as the same evil spirits that infect the world today were prevalent in those Bible times, despite Samuel's efforts to warn his countrymen of their folly. The Bible gives many examples of how God rewarded His believers with victory in battle, but when their heart turned to earthly things as a substitute, a common occurrence in Samuel's day, Israel suffered greatly with huge losses inbattle.
Even the Ark of God, brought into battle before the days of King David couldn't secure victory, for God knew that the Ark was just a symbol and the hearts of his people weren't attuned to Him. The result was a major defeat and the loss of thirty thousand soldiers, a huge number even by today's standards. When God is not in the heart, yet He is asked to provide His protection, perhaps He uses the disaster to send a lesson. He does, after all, expect us to live in His image.
This same message applies today just as well as it did in Bible times. And today, we are just as likely to act in the same way the ancient Israelis did, asking God to help us when we don't really turn over our heart to Him. Look at the strife in the world today and think about it. If ever the world needed a "Come to Jesus Moment", today is the time. We can develop and create unbelievable things, but if they are not put to use as God wishes, they will never get us where we should want to ultimately be. Where is that someplace? It's living in His presence for Eternity after earthly life is done.
And keep in mind one other thing. Even though we are expected to live in His image, sometimes we run into others who have no intention of living for God. He expects us to discern the difference and he gives us this ability when we truly turn to Him. And nations also must remember that, for when evil is active, sometimes it takes total destruction to end it. Peace is a worthy cause and it's something we should always strive for, but peace at any cost is not what God has in mind. Freedom with God is more likely what he wants us to attain.
Lord, We thank you for your mercy and grace and we ask that you would help us to keep our hearts open to you and live our lives in a way that would please you. In Jesus' name we pray, Amen.