When talking about ethics, Barth always started with God. His belief was that God's being (as the tri-personal God who is love) and God's doing, are inseparably linked. In Church Dogmatics he proclaimed: "God is who He is, and lives as what He is, in that He does what He does."
Barth then noted that we have in the person (being) and work (doing) of the Incarnate Son of God, Jesus Christ, the definitive revelation of who God is and what God does. Barth then noted that through our relationship (union and communion) with Jesus we participate by grace in God's own being and doing. Thus Barth approached Christian ethics as our participation in the love (being) and life (doing) of Christ himself. This relational view of ethics, grounded in a tri-personal, relational view of God, is fundamental to Barth's Trinitarian, Incarnational theology.