The Gospel of John was written to convince people that Jesus is the Christ so that we would put our trust in him. In this sermon, your focus is on explaining the mystery of the incarnation—how God took on flesh. Since there is a lot of confusion in many churches regarding the incarnation, your sermon should also address particular doctrinal errors that are prevalent in your local community.
14 And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth.