mark wrote as someone who was getting his information second hand from someone who was with Jesus and was used to help those who thought they were not good enough to be Christians, Matthew wrote as someone who was actually with Jesus and focused mostly on the teachings of Jesus
Its important to know the difference because it gives a better understanding of the messages.
Matthew was written to the Jews and portrays Jesus’ kingship. Mark focuses on Jesus as the Messiah
Matthew was written “first to the Jews, then to the gentiles” as Paul says in Romans. Mark was written for the people of Rome. Matthew focused on a chronological list of Jesus’ life works, while Mark used a more thematic style. These distinctions are important because they reach different people groups, therefore helping to further the kingdom of God.
Each author had a specific audience he was writing to and therefore presented a different aspect of the Messiah to each. Matthew was writing to a Jewish audience and presented Jesus as a suffering servant as a means of relating the prophecies of the Old Testament picture of a need for the Messiah to serve and suffer so that humanity could be restored to a right relationship with Gos Almighty. Mark addresses his audience with the portrayal of Jesus in His kingship as a fulfillment of the Old Testament promise of an eternal king from the line of David.
Mark seems to be written to a more Roman audience, and works to establish the humanity and divinity of Christ. Matthew on the other hand works to establish Jesus as the Messiah primarily because he is very much writing to a more Jewish audience. That’s why, although not written first, Matthew is the first gospel because it seeks to be the connective tissue between the Old and New Testament because that is the way one would connect to a Jewish audience.
Mark portrays Jesus as the suffering servant while Matthew presents him as a King worthy to be worshiped. If Mark’s audience were Christians suffering persecutions or difficulties because of their faith it would be encouraging to know that Jesus also suffered along with how he handled it. For Matthew, who was speaking to Christians who had been rejected – passionately – by Jewish non-Christians, then then would be encouraged knowing the truth of their Messiah.
The key distinctives of the gospels of Mark and Matthew are how they portray who Jesus is and the audience they were writing to. Matthew was writing primarily to the Jews and portrayed Jesus as a King. This was important because they were looking for their Messiah to be a King and Matthew showed how Jesus fit this description and so much more. Mark was writing to the new Christians in Rome and showed Jesus as a servant as well as a patient teacher to the disciples. This was important because they (and we) may have felt ill-equipped to follow Jesus. Mark provided Jesus’ parable explanations for his disciples and gave encouragement to believers that they don’t have to be perfect.
Matthew is the Gospel of the King and is written to describe Jesus as the messiah, with decendency and a life that reflects and addresses the expectations established in the Old Testament. Mark presents Jesus as the humble servant. Each of these books writes to address these aspects of the life of Jesus to paint a complete picture of Christ, along with Luke and John.