Religious or not just take a minute, and read this.
I'm not judging or preaching, just pondering. (if you've got a minute read this, if you've got two tell me what you think of it.)
God created us all with a choice, to serve Him or to serve ourselves. True evil in our world comes from the later of the two choices. That is truly what we are here to learn. When you follow the first of all the directives that Jesus put forth, IE: When Jesus was asked " Teacher what is the great commandment in the law?" Jesus said to him, "You shall love the Lord your God with all your heart, with all your soul, and with all your mind." "This is the first and great commandment." Matthew 22:36-38. When we follow this commandment we are bound to do God's will. Within that state of mind there is no doubt, all of our fear, and hatred, and self serving nature is defeated. When true evil manifests it is from these that it is born. When you look to any sin you have committed throughout all of your existence you most probably will come back to one of these. Especially fear. When you keep your mind, your heart, and your soul focused on loving God there is no room for evil.
I believe that the lesson that we are here to learn is just that; Doing YOUR will allows evil to gain a handhold on your life. Doing God's will serves God and evil is defeated.
If God were to remove evil, He would in effect be taking away your choice, your free will. At the very least removing evil would remove any opportunity for us to see the consequences of our actions.
In closing I would just like to point out that as men, and women we may never be able to completely ignore our impulse to take control and go our own way succoming to our base impulses, and fears, it is very difficult to completely surrender your will to God. Those that have are said to reach sainthood. Those that have not are still loved and cherished by God. That is what grace is, only by the grace of God are we saved. Hopefully we can gain faith in our lives, and accept His will, day by day, a little more. Because I believe that the more we do, the less evil will be with us.
If you look at it this way I guess the question would be better served; Why we as the children of God, allow for evil to persist?
F.Michael Sigler