God speaks a free and loving “Yes” to Jesus Christ; the event of this “Yes” is God’s trinitarian life, and its corresponding echo is a creative and redemptive “Yes” to humanity, so that God’s relationship to humanity is an echo and an analogy of God’s relationship to Jesus Christ.
“It took Barth decades to write the Church Dogmatics; and it takes a couple of solid years to read the whole work through”; here’s a one sentence summary as offered by Ben Myers