Why are there four accounts of the life, death and resurrection of Jesus? Because each Gospel account has a slightly different emphasis for different audiences.
Matthew wrote for a Jewish audience. God chose Abraham’s descendants, Israel, to bring the Messiah into the world. They lived under the Law of Moses for about 1,500 years, Jesus Himself being subject to it. But Jews had to be convinced that Jesus fulfilled the Old Testament prophecies about the Savior and His kingdom. That’s what Matthew’s Gospel shows.
Mark seems to have written for a Roman audience. Rome ruled at the time of Christ, and the Gospel spread quickly throughout the Roman Empire, possibly with the aid of the shortest account of the good news. Roman people weren’t as interested in the subtleties of culture and learning. They were men of action. Mark’s Gospel follows this pattern—lots of activity and lots of commands, little explanation.
Luke, the physician who often traveled with the apostle Paul, was likely of Greek heritage, Luke being a Greek name. He presents Jesus as the perfect man—in temperament, teaching, behavior, endurance, learning. This appealed to the Greek mind.
John’s Gospel is different. It’s more philosophical. The others are aimed at specific ethnic/religious cultures and mindsets, but John’s Gospel is cosmopolitan. It presents Jesus as the Son of God. John includes lengthy speeches by Jesus in which the Savior explains Himself, and the fourth Gospel includes several miracles which confirm the Lord’s claims.
Though different in specific content, all four Gospel accounts have the same ultimate aim: proving that Jesus of Nazareth was both the Savior and the Son of God. They contain information to create faith in Jesus, but their purpose is not to show sinners how to act on that information. Only one book in the New Testament does that: Acts.
After Jesus rises from the dead, He tells the men who’ll be apostles what they’re going to do and teach (Matt. 28:18-20; Mark 16:15-16). But the four Gospels don’t chronicle the apostles carrying out their orders. Acts does. Before He departs, Jesus tells the disciples to go back to Jerusalem and wait for “power” from heaven (Luke 24:49). That power does not come, and they do not preach the Gospel, until the events in the Book of Acts.
The Gospel is the good news about Jesus’ atoning death and resurrection. Using passages like John 3 to learn specifically how to respond to the Gospel to be saved presents a chronological problem—Jesus hadn’t died yet. The books of Matthew, Mark, Luke and John aren’t intended to tell us how to be saved—they tell about the One Who provides salvation. It’s in the book of Acts that the apostles take the good news of salvation to the world.