Karl Barth develops his christology in terms of Christ's priestly, kingly and prophetic work. As priest Christ justifies us; as king He sanctifies us; as prophet He calls us. In this seminar course its members will examine Barth's account of calling, its occurrence and its goal. Barth develops his understanding of calling in terms of witness. The course will attend to Barth's account of Jesus Christ as the true witness and follow this theme as Barth develops it in an exposition of the book of Job. The course will next examine how Barth explains how Christians are drawn into Christ's witness, themselves being constituted witnesses. The course will conclude with Barth's description of sin as falsehood, which arises from different sorts of denials of Christ's prophecy and is overcome only by God's judgment upon it. The readings in the course will be in Church Dogmatics IV/3.