When someone says that God is perfectly good, I feel they are somehow saying that God is humanly good; that he is well behaved in a human sort of way, following all the human rules: no killing, taking perfect care of his neighbor, treating animals perfectly well, no slavery, no destroying cities, does not cause pain to others, treating others equally, giving his perfect wealth to the less fortunate, and so on. He is perfectly well behaved.
One realizes the absurdity of such a saying when thinking of God as a well behaved lion. He roars perfectly loudly, he has the perfect number of female lions to procreate with, he perfectly eats his meals before the female lions, he runs fast across the African plain, he perfectly sharpens his teeth on the bones.
God has no more need to act like a well behaved human than he does a well behaved lion. Only things that are ordered can possibly be perfect. Ordered things have a certain way they should be. But God is not ordered. If he was, we could ask who ordered him. Such a question would reveal a being more ultimate than he, which would indicate that he was not God.
What about God as God; are there certain sets of actions that typify what it means to be God? Does God create because that’s what a God does? Does God have a nature, a certain set of actions that he does or else he is not God? I think the answer to these questions is no, God is not ordered nor does he have a nature.
All this means that God is not a moral being. He is obliged neither to make your life any better or any longer. When we say God is good, we are not saying he is well behaved as a God should be. We are saying that God is goodness itself, the source of all created good. God who has no nature and is not ordered created things with natures, things ordered. When a man sets his face in the direction of God and says that God is good, he is seeing his human reflection from the source of his human goodness. And while looking there he sees, as much as he is able to see, how he ought to be. God is reflecting back to that man the way he is made. But, it is an error to project that same reflection upon God and say that this is how God is good.
God is indeed good, but not in any created sense.