The first Gospel, though probably not the first to be written. Its most likely date is between 75 and 85  AD, and though it is associated with Matthew the apostle, it is not known for certain whether he was the author. Most scholars believe that the main sources are Mark's Gospel and a collection of the sayings of Jesus known today as Q, but this remains a hypothesis, and it is more helpful to consider the book's shape and purpose. Matthew's Gospel is built round alternating sections of narrative and teaching, with five main blocks of teaching (chapters 5-7, 10, 13, 18, 23-5) woven into the story of Jesus' life. This arrangement indicates that Matthew's primary aim was to tell the story of Jesus, but with his own emphases. Four aspects of this teaching stand out. First, Matthew presents Jesus as Messiah and Son of God. As Messiah, Jesus fulfils the Old Testament (5:17) and all the promises of salvation and restoration come to fruition in him. This takes place because he is God's Son (3:17; 16:16) and God's obedient servant. Jesus especially fulfils the role of Isaiah's Suffering Servant (8:17; 12:17-21), being fully obedient to his heavenly Father both as a human being and as his Son. Jesus also makes known the kingdom of God, or as Matthew calls it, the kingdom of heaven. Second, Matthew sets the story of Jesus in the context of God's purposes throughout history. Jesus represents the climax of God's work in the Old Testament, especially in his death and resurrection, and continues his own ministry in the church. Jesus' continuing presence with his people is specially emphasized (1:23; 28:20). Third, Matthew understands Christian faith in terms of discipleship, emphasizing Jesus' final instruction to go and make disciples from every nation. No other Gospel devotes as much space to Christian behaviour, which should be characterized by love and righteousness. Fourth, Matthew regularly quotes the Old Testament. This practice is partly explained if Matthew was writing for a mainly Jewish audience, but more importantly Jesus as the living Word of God is regarded as the personification of the Old Testament. According to Matthew, Jesus' person and work could not be understood without the Old Testament.