Everything that happens is not God's will. Sin that we commit is not God's will. Rape,murder, abuse are not what God wants for us. This world is not perfect and often we are allowed to do as we please even if it may harm others.
God's knowledge is perfect. Our knowledge is very limited. A child who lives a short life might be pitied here on Earth but may actually have an easier time choosing a right path since all children are innocent. Remember this life is incredibly fleeting. What is 70-90 years compared to eternity? After death comes the most incredible experience of pain free, anxiety free, guilt free, peace with God.
God is always in control which is different than saying that everything that happens is his will. Nature produces beautiful things and terrible disasters often the same mechanism that causes us pain is the reason for something incredible as well. Remember we are only here for a short time. It's what we do, how we life and in whom we hope that is important.
