When I see the beauty of the Universe, and how God created order out of chaos, I see God as good. When I see God take the consequences of evil, and remake them into an orderly plan for good, I see God as good. In my own life, when I see God take an impossible and complex situation, and work it out in an orderly and controlled way for good, I see God as good.
But, then as commenter Rob reminded me, there are times when that is not enough. For all the times I quote “in all things God works for the good of those who love him, who have been called according to his purpose”, I still do not understand. I do not understand the horrors of World War II. I do not understand a hurricane, a tsunami, a tornado, or an earthquake. I do not understand rape, murder, or those who hurt children.
It is in those times, that good only comes through the cross. This is the mystery that we never quite can grasp. We only get shadowy glimpses when God opens our eyes and allows us to see.