Evil and Omnipotence

J.L. Mackie states the problem like this "If God is omnipotent (all powerful) and wholly good than why does evil exist?  The four arguments he cites are 1) Good cannot exist without evil. 2) Evil is necessary as a means to good. 3) The universe is better with some evil in it than it could be if there were no evil. and finally 4) Evil is due to human freewill.  There are several problems to each argument as Mackie sees it.  Mainly that each argument somehow either questions God's power or his goodness, ie.., if humans can see that evil is a problem why couldn't God see it?  Or if Evil was necessary did there need to be so much of it?  Or in the case of human freewill could God have just made us with freewill when we were about to do something bad?  Mackie only brings this questions to the readers attention he never asserts a final position on any of them, he leaves that up to the reader.  I did find this interesting analogy about a man who creates a robot with the capacity to learn and make decisions.  He also makes it with abilities like the ability to kick, with the hopes that the robot would kick balls back to little children in the playground, or maybe kick grenades out of harms way for soldiers.  The robot however develops a penchant for kicking puppies, it goes out of its way to hunt down the cutest and fluffiest puppies just to kick them.  Maybe God did not design us for doing evil but we just acquired a taste for it.