The notion of God includes goodness, and the notion of goodness includes diffusiveness, or the giving out of goodness.  Without goodness God would cease to be a deity, and without diffusiveness He would cease to be good.

The being good is necessary to the being God, for goodness is nothing else (in its simplest form) but a strong inclination to do good;  either to find or render an object good according to the inclination of the finder’s own good nature.  Goodness is a readiness to communicate itself, not for its own interest, but the good of the object it prevails upon.

And so God is good by nature, and His nature is not without activity.  He acts consistently with His own nature:  “You are good and do good” (Psalm 119:68).  And nothing benefits Him by communicating Himself to others since His blessedness is as great now (with all creation looking on) as ever it was before the erecting of the world.

From the book “Boundlessly Good”