Why does God allow evil in the world?

God allows evil in the world for three basic purposes.  First of all God created evil (Isaiah 45:7), being Satan, so that all of His creation would have a choice whether to follow God or not.  If there was no choice, and no free will, then everything that God created would be like robots and there would be no true love for Him.  Secondly, we need to remember that God is good (Psalm 143:10) and that evil is the absence of God’s presence (3 John 1:11).  Evil thrives when God’s creations run from Him and rebel against Him and follow Satan.  Finally, if God was to get rid of all the evil in the world, there would not be anyone left.  God in His mercy is patient enough to tolerate the evil so that those who wish to come to Him will be able to be saved and have their sins forgiven (2 Peter 3:9).  Everyone who thinks that God should just take away everything that is evil may not realize that if He does so He cannot just pick and choose, but judge righteously across the board, and that they will be eliminated as well.  Thank God for His mercy instead of asking why He is merciful.