The Gospel story creates, which is to say re-creates, the prelapsarian garden of Edenic pleasure, and thus Edenic joy.
The idea he is conveying is that God through the gospel is putting all things right again. He is restoring us back to the place of pleasure, Eden means pleasure. He is releasing to us the joy of our first love. What level of good news is this?!
The simple, yet profound, idea that God in Christ has fully restored us to the garden of Eden is life-changing.