In the introductory material of his commentary on The Gospel According to John, D.A. Carson includes a helpful section on preaching from the fourth Gospel. Carson reminds preachers and Bible teachers that John's Gospel is about Jesus; his person and work and "his place in the sweep of redemptive history". He then remarks,
“…John’s stated purpose in composing the Fourth Gospel is not that his readers might believe, but that his readers might believe that the Christ, the Son of God, is Jesus, and that in believing they might have life in his name. To hammer away at the urgency of belief without pausing to think through what it is John wants his readers to believe and whom it is he wants them to trust is to betray the Gospel of John. Preaching from the Gospels is above all an exercise in the exposition and application of Christology (102, emphasis in the original).