There are four Gospels for a reason. Their existence isn’t an accident. The fact that more than one was written suggests that each writer had a slightly different audience in mind. Examining their content validates that hunch.
Unlike other Gospels, the Gospel of Matthew nowhere states a specific purpose or occasion for Matthew’s enterprise. Determining Matthew’s audience and objective can only be accomplished by careful reading. Matthew references the Old Testament more than the other Gospels, with special interest in messianic themes such as establishing that Jesus was the “son of David” and how his life fulfilled Old Testament prophecies about the Messiah. Matthew uses distinctive phrases from Jewish literature (e.g., “Father in heaven”) more than other Gospels. He includes Jewish customs and terms without explaining them to readers (23:5, 27; 15:2; cf. Mark 7:2–4). All of these things and others indicate that Matthew was writing to a Jewish audience to convince them that Jesus was their messiah.
One of the unusual things scholars have noticed about Mark’s Gospel is the frequent use (forty-two times) of the Greek adverb euthus (often translated “immediately”). Mark constantly presents Jesus as a man of action—getting things done with expediency. Mark omits Jesus’s birth and childhood. There is no genealogy. These things don’t matter to Mark’s audience. He writes to people more concerned about what Jesus does than who he is—very different from Matthew. These features make Mark’s account conform to Roman cultural values. This is especially important because of the way Jesus died—as a criminal by the heinous method of crucifixion. Mark needs to explain why the crucifixion happened to this audience, and so he blends a description of a man they can admire with a defense of the gospel.
Luke tells us at the outset that he is writing to a Greek friend, Theophilus. Luke (Loukas) is a Greek name. Luke uses Greek terms not found in the other Gospels. He seeks to reach a Hellenized world, not Jews or Romans, with the Gospel of Jesus. His strategy is a lengthy letter—his Gospel—to Theophilus, that he “might have certainty” concerning what he’d heard about Jesus (Luke 1:1–4).
Lastly, we come to John, the Gospel with the most unique material. John’s agenda is nevertheless transparent. His Gospel devotes the most concerted effort to presenting the deity of Jesus Christ. Only in John do we get the seven “I AM” statements of Jesus, a phrase hearkening back to the name of God given in the burning bush. John includes unique statements uttered by Jesus: “I and the Father are one” (10:30); “whoever has seen me has seen the Father” (14:9); “the Father is in me and I am in the Father” (10:38). And John tells us why. He wrote his Gospel so that readers “may believe that Jesus is the Christ, the Son of God,” so that they “may have life in his name” (20:31).