Jesus of Nazareth, also known as Jesus Christ or Yeshua ha-Nozri, was an early first-century Jewish prophet. Many of his modern followers believe that he was the "son of God" (a term with a contested meaning), or God incarnate.
There is debate among scholars as to the age and authorship, and therefore validity of the Bible record of Jesus. He is mentioned in two places in the writings of Eusebius, an early Christian historian. In the works of Josephus (a Jewish historian), Jesus receives a paragraph; however, this was almost certainly embellished by Medieval copyists, as it is uncharacteristically aggrandizing; the original paragraph was probably either much shorter (a sidenote) or conceivably condemnatory.
Some authorities have speculated that the book of Mark was written by an eyewitness but there is no conclusive proof of that (although there is evidence that Mark is earliest of the canonical gospels). The book of John contains a number of stories about Jesus and a substantial amount of dialog attributed to him, an appears to have been written around the end of the second century.
It is believed that prior to the writing of the canonical gospels, so-called "sayings gospels" circulated. This hypothesis was confirmed with the discovery of the Gospel of Thomas, which is written in the form of short exchanges between Jesus and his disciples, with little "context".
 Notes on the Time Period
Technology was changing very slowly in comparison with the world today. Productive capacity of the land was more or less fixed, wealth of a country depended heavily on food production, and the economy of the time looked very much like a zero sum game. In consequence, if one man was rich, others necessarily were poorer in consequence.
The political situation in Israel must also be considered. For centuries there had been a divide between the pro-Aaron priests and the anti-Aaron priests. This can be seen most clearly in the writings of the "minor prophets". The pro-Aaron priests had gained power and successfully centralized Jewish religion in the Temple, and had become deeply concerned with form and procedures, and assuring that God was appeased through offerings of the right sort at the right time. The anti-Aaron priests and prophets were far more concerned with the well-being of the common people, who were as disenfranchised as they.
The royal family -- the house of David -- had fallen from power when the southern kingdom went into exile. The traditional priests-- the men of the Levite clan -- also disappeared at the time of the exile. By the time of Jesus, the Maccabees, with no apparent connection to the house of David or the traditional Levite priesthood, had risen to power as priest/kings. King Herod I, though subordinate to Rome, had married into the Maccabees and converted to Judaism, and so was as legitimate as any of the late-BC Jewish kings. He was, however, on the pro-Aaron side of the political divide, represented by the group (Zadok-ees/Sadducees) who claimed to have Zadok as their ancestor.
 Philosophy of Jesus
When we turn to the philosophy espoused by the quotations attributed to Jesus we are on much firmer ground. Based both on internal evidence and on the political situation at the time, there's no reason to doubt that the quotes preach love of God and of fellow man, and certainly pacifism. I've included a few brief quotes from Bible verses to show the general direction of Jesus's teaching.
- "Love your enemies, do good to those who hate you, bless those who curse you" -- Luke 6:27-28
- "The second [commandment] is this: 'Love your neighbor as yourself.'" -- Mark 12:31
He also preached against wealth, and in favor of charity.
- "Go, sell everything you have and give to the poor" -- Mark 10:21
- "It is easier for a rope to go through the eye of a needle than for a rich man to enter the kingdom of God" -- Mark 10:25
- "Give to everyone who begs from you" -- Luke 6:30
He also warned His disciples against using force over others
- "Ye know that the princes of the Gentiles exercise dominion over them, and they that are great exercise authority upon them. But it shall not be so among you: but whosoever will be great among you, let him be your minister; And whosoever will be chief among you, let him be your servant"
And on one occasion Jesus apparently preached against using honorifics.
- "But you are not to be called rabbi, for you have one teacher, and you are all brethren. And call no man your father on earth, for you have one Father, who is in heaven." -- Matthew 23:8-9
While one can argue about the strength the sentiments expressed in the above, very brief quotes, one certainly can't find anything indicating the slightest support for the opposite sentiments. Never are any quotes given that said anything in support of war, of physical retribution, of taking vengeance for offensive acts, nor of abusive or exploitative behavior toward the poor, nor anyone else. Nor is there any preaching in favor of any sort of elitist stratification of society.
Strangely, in the centuries after Jesus, while mainstream Christians became convinced of Jesus' divinity, they also apparently rejected his teaching. The Catholic church adopted the title of "father" for all priests, apparently in direct violation of the teaching of Jesus. The Crusades, encouraged by the Pope, were fought in Jesus' name, and began with a Crusade against fellow Christians who took a different view of who Jesus was. They were long, bloody, destructive wars with the goal of capturing land considered "holy" from religious opponents -- it is hard to imagine Jesus ever speaking in favor of such an action. Much later, the thirty years' war was fought in large part as a war between Catholicism, Lutheranism, and Calvinism -- it presents the absurd spectacle of people going to war over the question of the proper way to worship a pacifist.
In our own time we are faced with a fundamentalist Christian movement which supports preemptive wars of aggression, fought to make us safer by destroying our enemies before they make the first move. This may be a politically wise course, but it's very hard to see how it can be squared with the views expressed by Jesus, and it's hard to imagine how anyone could claim that Jesus would condone such action.
Background material for this article was drawn from various sources, including the Bible (various translations), the Apocrypha, the Pseudepigrapha, Charlesworth's commentary on the Pseudepigrapha, the "Five Gospels" and the Historical Jesus Project, the Cambridge Companion to the Bible, the Merriam-Webster Biographical Dictionary, Josephus' Antiquities and Jewish War, and a large number of web sites,including but not limited to Steve Carlson's cluster analysis of the New Testament, the Wesleyans' excellent site, New Advent, the Synoptic Problem Home Page, the World Without Q, the Gospel Parallels site, and of course the very useful Bible Gateway site.