Jesus first teaches the church’s true name, then highlights the essential identity of that name—the gospel. The Savior explains that, if the essence (gospel) is not his, then men called by that name will not be called into Yahweh’s presence, but rather into the fires that destroy the wicked at the end.
Jesus repeats that he has taught them the true gospel. Therefore, the true gospel also has the Messiah’s true name. As Christ’s representatives, the twelve bear the name and express the gospel essence.