It is interesting to note how each Gospel has a slightly different emphasis in terms of the picture that it presents of Jesus. Each Gospel writer was trying to present Jesus to a particular audience, and based on the varying nature of that audience, different aspects about Jesus and his ministry are stressed.
The primarily Jewish audience of Matthew for example shapes the way in which that Matthew attempts to prove to his Jewish readers that Jesus is their Messiah. Clearly the way in which all of Jesus' actions and words are presented as fulfilling various Old Testament prophecies supports this.
Mark, however, seems to stress the role of Jesus as being a teacher. Even though it is the shortest of the four gospels, the word "teacher" in its various forms are applied to Jesus far more in this gospel than in others. In addition, another principal theme of this Gospel regards the humanity of Jesus, combiend with his divinity.
Luke's Gospel had a mainly Gentile audience, which stresses the place of the Gentile Christian in the Kingdom of God that Jesus came to announce. Thus it is that throughout the Gospel Luke places emphasis on social outcasts of the day, such as the poor and foreigners.
Lastly, the Gospel of John is recognised as being very different from the other three gospels, and is not regarded as being a "Synoptic Gospel," which is the title given to the other three to indicate their similarities. Jesus is presented in very philosophical terms to appeal to a Greek audience, which is why the first chapter famously refers to Jesus as "the Word."