God’s eternal life as Father, Son, and Holy Spirit is a thing of infinite blessedness and perfection. There is a blessed God at the core of the glorious gospel.
God in himself is perfect, and perfectly happy. Being perfect, he cannot essentially improve. He can make happiness and blessedness available to his creatures because he always already has it.
This vision of a God with no unmet needs is a glimpse of the depths of the living God and the fund out of which he spends himself so freely in the economy of salvation.
The Deep Things of God: How the Trinity Changes Everything (Wheaton, IL: Crossway, 2010), 94
(HT: Of First Importance)