As you come to the New Testament the first three books you encounter (Matthew, Mark and Luke) are referred to as the "synoptic" gospels. They are called the "synoptic" gospels because for the most part, they have a "similar view" of the life and ministry of Jesus. Though they account for much of the same narrative regarding the life and ministry of Jesus, they are not identical, nor are they intended to be. They assemble the accounts in different contexts, and contain different amounts of detail, but they are all important. God always seeks to establish a matter on the testimony of 2 or 3 witnesses, so having these 3 synoptic gospels about the life an ministry of the Son of God is in no way redundant.
Matthew’s gospel communicates to us the life, ministry, death and resurrection of Jesus in the fulfillment of the Old Testament Scriptures. From His lineage, to His birth, to His miraculous ministry, to His teachings, to His crucifixion, Matthew will time and time again point out that these things happened “that it might be fulfilled which was spoken by the prophet…”.