Critical study of the Gospels has sought the human Jesus behind the mythic and theological symbols of Christianity. Analysis of material common to Matthew, Mark and Luke and of sayings common to Matthew and Luke (designated 'Q', German Quelle, 'source') has provided an explanation of the sources of the synoptics (Fitzmyer, The Gospel According to Luke (I-IX), pp. 63-106). Mark was the earliest narrative account of Jesus. References to war in Judea (Mark 13:5-8, 14-19) as well as to persecution (8:34-8; 13:9-13) suggested that it was written during Nero's persecution of Christians in Rome or the Jewish revolt in Judea (c. 66-70 CE; see Donahue, 'Windows and Mirrors'). Independently of each other, Matthew and Luke expanded Mark. Their sayings material (Q) came to each evangelist in different forms (cf. Matthew 5:3-10 and Luke 6:20-6; see Betz, The Sermon on the Mount, pp. 22-44,105-10)- Matthew and Luke sometimes substituted the Q version of an episode for Mark's (cf. Mark 1:12-13; Matthew 4:1-11 and Luke 4:1-13). In other cases, oral tradition underlies the agreements of Matthew and Luke against Mark (e.g. Mark 14:65; Matthew 26:68; Luke 22:64).

When we think of someone as a teacher, we usually think of that person as offering instruction in a school. Pupils are enrolled in the school and follow a system of education established by the school. There were some schools in Jesus' time that would fit this picture. Up until age twelve both boys and girls who lived in cities and towns spent their mornings in schools where they learned the basics of reading and writing. After that age, only boys of wealthier families continued their education. They were sent to teachers who drilled them in the classics, especially the epic poets Homer and Hesiod, and taught them how to speak like educated men. They would study and seek to imitate famous orators like Demosthenes. Rhetoric was the only training for government or public service. Young men learned the duties and behavior appropriate to various offices by imitating older men, especially natural or adoptive fathers and uncles. Sons of craftsmen learned their trade as apprentices. Schools did not train people for later life. Similarly the sons of priests learned what they needed to know for service in the Temple from their fathers.

Jesus, however, did not establish a school with a philosophical doctrine or special method of interpreting the Law. His followers learned by observing what he said and did in different situations. The Gospels refer to a group of Jesus' disciples as the twelve. Mark 3:14–19 pictures the twelve as having been selected from the larger number of followers. They are shown receiving special instruction from Jesus (Mk 4:10; 9:35; Mt 11:1).

Jesus spoke with a prophetic voice to all people. Understanding his message did not require special education or even a life that had been marked by holiness in a special way. Ordinary people heard Jesus' words as the word of God addressed to them. Jesus did not use a “scholarly” or “technical language” such as we find in philosophical writings of the time or in legal disputes over the meaning of the Law. The references to the Law and other images taken from the Hebrew Scriptures are ones that would have been well known to Jesus' audience. Other images in Jesus' teaching reflected the daily life and experience of people.

Since we do not live in Jesus' world as part of our “everyday life,” we often have to use the findings of archaeology and the study of other writings from the time to understand Jesus' images. Even then we may not be sure whether Jesus is simply reporting what people did or whether he has exaggerated a commonplace situation in order to make a point. The well-known Parable of the Sower (Mk 4:3–8) is a good example of this problem:

Established “schools” had a process by which persons became teachers. They would have to spend years as students or disciples of a famous teacher. An outstanding student would then succeed the master. Others might eventually form their own group. We have already seen that Jesus did not come out of such a school. He had not studied the Law with a famous scribe or been part of a group devoted to interpreting the Scriptures like the Pharisees or Essenes. This fact about Jesus lies behind the question preserved in John 7:15: “How does he know letters, since he has not been taught?” This comment does not imply that Jesus was illiterate. He would have been taught to read the Torah scrolls as well as the other forms of reading and writing common in elementary education. But it suggests that Jesus had not been taught how to interpret the Scriptures according to the principles of some school.

Jesus' reply was that he has been taught by God, the one who sent him. Anyone really concerned with doing God's will should recognize the source of his teaching and follow him (Jn 7:16–17). Another scene in John shows that early followers of Jesus also had to face the accusation from Jewish teachers that they were ignorant and could not presume to tell others the truth about God's will. This conflict is “acted out” in a story in which a blind man defends Jesus before hostile Jewish teachers. He is eventually thrown out of the synagogue for believing that Jesus is “from God” (Jn 9:13–34).

Disciples of a famous teacher expanded and interpreted their master's teaching to answer questions that arose after the master's death or to explicate unclear teaching. The lives of famous teachers were expected to reflect their doctrines. Combining episodes from a teacher's life with samples of teaching provided an effective way of passing on the views of a particular group. Frequently, biographies of famous people were framed to bring out the lessons that one could learn from the individual's life.

Scholars disagree over whether or not the Gospels should be considered biographies of Jesus, but they do agree that episodes from Jesus' life have been used to illustrate his teachings. The evangelists have also put together traditions that they inherited about Jesus in larger units, which provide interpretations for the individual sayings or stories. Sometimes when a saying or story occurs in more than one gospel it is easy to see that each writer has handled the material differently. Since early Christians believed Jesus to be the Son of man, exalted at God's right hand and coming to judge the world, an evangelist may substitute “I” for the phrase “Son of man” in a saying (e.g., Mt 16:21; contrast Mk 8:31 and Lk 9:32). We noted in the preceding chapter that Mark arranges sayings about the end of the world in Chapter 13, so that Christians will not mistake the destruction of Jerusalem as a sign of the end of the world.

We have already treated the central image in Jesus' preaching, the Reign of God. Jesus spoke of the hopes that many people had for a judgment that would finally destroy all evil and permit the righteous the peace and joy in God's presence that goodness deserved. He taught that God's presence could be experienced even in this world if people would live with mercy and compassion, if they would learn to rely on God's goodness rather than on human systems of power. Jesus did not promise that such a life would lead to riches and success on earth. His own life demonstrated that humility and suffering were part of a life dedicated to God (e.g., Mt 5:3–11).

Jesus used images like that of the heavenly Son of man to reassure his followers that success in God's eyes could not be measured by human standards. God's own judgment would vindicate everything Jesus did and taught. The early Christians experienced the truth of Jesus' vision of God when they learned that Jesus' humiliation on the cross had been turned into heavenly glory at the right hand of God. This conviction meant that Jesus' words had the authority of divine revelation behind them.

In this final chapter, we are going to survey some of the other themes of Jesus' teaching that are particularly important for Christians today. The theme of justice and solidarity is especially prominent in social ethics and liberation theologies from Third World countries. The problem of bringing about justice in a corrupt world is understood to require that people overcome the divisions that separate and create hostility between different groups.