If there is any true happiness outside of God in this universe, it is happiness derived from Him. He desires nothing more than what He has because it is impossible for Him to be more or less blessed than what He is.
The blessedness of God is the fountain from which we drink for truest happiness. Because His blessedness is the abounding of all good things, when He created the world, He created all things good and, thus, all things blessed.
Sin brought misery. But God sent his Son to deal with sin and misery to make us like Himself — blessed, happy, content, fulfilled, and joyful.
John 3: 16 "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life."
