The free will is the real problem. If we go back into the history there is not a single period where people did not have conflict with each other.People killed each other because of this free will. Free will was in God's plan when he created the human beings. Look at all the prophets they were running here and there to save their life.The Prophet family most of them were killed, so were the companions of the prophets.Millions of people were killed by human beings in the last few wars. There is no sign that that this will ever stop. The only time it will stop is when God take away the free will from human beings and proclaim that the THE WILL BE HIS only. That day will be a blessed day.