If evil is that which displeases God, this it is not possible for Him to be evil. He is the standard, the ruler, the inch, the ethical metric system…
This is wordplay, but it isn’t just wordplay. If there is an infinite creator God who spoke the universe into existence from nothing, then what standard of goodness and evil could possibly exist outside of Him? What could He be compared to? What scale exists outside His own creation, what entity to surpass Him?
An infinite God is I AM, and all else must be measured in terms of His nature, His loves, and His loathings. (N.D. Wilson, Notes From The Tilt-A-Whirl, pp. 94-95)