The Bible says in Genesis chapter 1, verse 26 that God created humans "in his image." He made us to have his characteristics. One of those is the freedom to choose--we can choose love or evil. If God is going to give free will to us, He has to allow for the possibility of us misusing that freedom, even if this means hurting others. God made things this way because the only other alternative would have been to make a race of robots that can't genuinely love. From the beginning of creation we see that humans have chosen to do wrong. Evil came into the world, along with unthinkable suffering. Suffering that is caused by evil choices are NOT God's fault; they are the fault of the one who chose.
God doesn't step in every time someone is going to misuse his or her freedom and hurt another because if He did then that person wouldn't really have the freedom to choose.
This freedom thing is a big risk. Therefore, the risk of freedom must be equal to its potential for good. The fact that humans have such an incredible amount of potential for evil shows that we also have an incredible potential for good. Yes, there are Hitler's and Sadam's in the world. But there are also the Mother Teresa's and the Martin Luther King, Jrs. You can't have the good ones without at least risking the possibility of the bad.
So, is it worth it? Consider this. In our own lives we all know that love can hurt. In loving others (parents, raising children, friendships, dating relationships, etc.) we often suffer a great deal. People reject us, they die, kids rebel, etc. And yet, we continue to love. Most regard it as cowardly, as tragic, and as terribly unhealthy not to do so. If a person never loved, he'd never suffer. But then again, he'd never really live.
But isn't God in this same position, only on a cosmic scale? To refuse to create a world where love was possible because the risk was huge seems to be beneath God. Love is really the only reason worth creating! It's not freedom for the sake of freedom that God values--it's love. Freedom is simply the only possible means to this end.
I hope this sheds some soft light on this HUGE subject. There is so much more to be said and studied. I hope you'll dig deeper*
