Jesus (nobody knows his family name--he probably didn't have one), son of Joseph and Mary, possibly of Nazareth, started a Jewish cult during the Roman occupation of Judea. There were a great many such cults, each with a charismatic leader. The historian Josephus lists dozens of them, including several that strongly resemble the Jesus cult, but the one following Jesus is conspicuously absent
1. So surely there were many more that were not listed. Many of these leaders were declared Messiahs, most often by themselves. "Christ" is a Greek word which means the same thing as Messiah--"Jesus Christ" simply means "Jesus the Messiah". Apart from the Gospel, there is no primary source that refers to the Jesus cult or Christianity. The earliest that's given any credence is from the historian Tacitus, writing in 116AD, who says that Nero tried to blame the great fire of Rome in 64AD on Christians, who were much hated and whose founder had been crucified by Pontius Pilate. We can't tell if this is based on real involvement by Christians or a revisionist attempt to pin it on them 52 years later, either by Tacitus himself or by later copyists looking for reflected glory. All four Gospels were written between 70 and 110AD, so it's entirely possible that Tacitus got everything he knew about Christianity from such later sources as these. It's also entirely possible that the cultists Tacitus claimed were blamed for the fire had nothing to do with Christianity and subsequent copyists have enhanced Christianity's involvement.
The Romans were very accepting of the Religions of those they conquered. As long as the Emperor joined your Pantheon and received due worship with its other members, your religion was welcome in the Roman family. The only monotheistic religion in the region, Judaism, got into a little trouble over this--the Jewish king at the time of their conquest, Herod the Great, was perfectly willing to put a bust of Caesar into all local synagogues, which satisfied the Romans. Where this ran into trouble was that a group called the Zealots felt that this relatively minor imposition was a slight to God
2 and became terrorists, killing Romans and any Jewish leaders that were willing to work with them. This terrorism worked as well as terrorism ever has: it provoked the Romans to destroy the Jewish homeland completely and carry a large fraction of the population off in slavery.
Jesus may have been one of these terrorists. The gospels do not tell us why the Romans wanted him dead, only that they did. His crime and punishment, sedition and crucifixion, were pretty much reserved for traitors against the state, such as these terrorists, so whatever the crime was, it has apparently been purged from the story for the benefit of the (largely Roman) audience. Nothing survives of this in the gospel apart from a bit of inter-factional rivalry. The Romans wouldn't have killed a faction leader unless they they thought he might be provoking violence. That Jesus doesn't make it, at all, into Roman records or the quite complete stories of Josephus, and that what little is known about him so flatly contradicts such a crime, suggests that the true story was either so inconsequential at the time to have not been noticed, or was somehow so embarrassing to later Christians that an unprecedentedly successful and complete revisionist purge was effected, or was entirely fictitious and made up by later people for some reason.
The completely fictitious version and the inconsequential version amount to the same thing. Whatever it was, the promulgators picked a completely inconsequential cult and elevated it. Most likely they did this to serve as a foil against some turmoil of the day. There were many issues that such a cult could be used to calm: Women had very few rights and Slaves had even less. Rome had been very accepting of residents of any of the colonies; it was traditional for free food to be provided to any Roman resident. All of these groups and more had banded together to demand more rights at one time or other. The Roman system of private armies was a complication too. Many, especially those from the colonies, would fight for whoever would pay them best. Rome was a constant, seething battleground of peoples feeling oppressed, and lots of them had weapons.
The philospher and statesman Lucius Annaeus Seneca (5BC-65AD) once said "Religion is regarded by the common people as true, by the wise as false, and by the rulers as useful." The invention of Christianity may have been the ultimate expression of that idea. Christianity is perfectly devised to appeal to all the disenfranchised groups: Women, Slaves, colonists, especially Jews and the followers of the Greek "Mystery" religions
3. All are equal in the sight of God, Jew or Greek, free or slave, man or woman (Gal 3:28 and many others). Jesus tells us to ignore insults and even violence, and love your neighbor and even your enemy. To honor your debts and your leaders, and not try to scam folks. Just exactly what a religion aimed at quelling rebellions needs to be.
Nothing gets people to band together quite so effectively as persecution and the many persecutions of Jews and Christians probably created more converts than they killed. That may have been the intent. The reason for the persecutions is obscure and the evidence of most of them, such as that of Eusebius of Caesaria, has largely been debunked. The strongest problem seems to be that Christians were often more tied to their church than to their families or the national interest. They were accused of all sorts of wicked deeds from devil worship to cannibalism and human sacrifice...and rumor mills will be rumor mills, and lynchings and stonings did occur. It seems to have reached a peak around 299AD.
A few years later, Constantine, inspired by his mother Helena, who had previously converted to "The Women's Religion", included a banner with a cross on it in his retinue at the battle of the Milvian Bridge. This battle won him the Emperorship and in gratitude he legalized Christianity. Told that it was a religion of the book, he asked for a copy. This was a problem. Every group had its own book, and they often conflicted
4. Constantine, now Emperor, ordered them to get together and work it out. On his orders, the conference of Nicea was convened in 325. The two leading factions were led by Athanasius and Arius. The Athanasians believed that Jesus was immaculately conceived and had been resurrected after his crucifixion. The Arians believed that Jesus was a divinely inspired mortal man who had died on the cross and remained dead. The leading Arian faction was mysteriously detained on the road from Alexandria and missed the conference, deciding its outcome. Arianism remained popular for about a century but Nicea gave the Athanasians the upper hand. By the time of Augustine, writing around 425, Arianism was too weak to survive and what little was left was killed off by the
Augustinian Heresy. Like many religious fanatics
5, later Christians set about purging the historic record of anything that doesn't fit their own ideas of religious purity. They didn't quite completely succeed but mostly.
1There was an attempt, apparently made by a German copyist at some point during the Dark Ages, to edit such a description in. But the style of the language is conspicuously different and copies lacking these suspicious extra passages have survived.
2The Roman demand that Caesar be treated as a God is entirely consistent with Jewish theology, so what the Zealots were angry about was much ado about not very much, and the Jewish leadership, Herod the Great in particular, understood that. There are lots of entities recognizable as demigods--Archangels, such as as Gabriel and Michael, for example.
3The Greek Mystery Religions are interesting. Paul seems to have embraced them and integrated their important ideas into Christianity. Later Christians actively suppressed them and most of what we know is indirect. The mystery God (each of dozens of sects had their own) is immaculately conceived and interacts with people as if one of them. He is later killed and seen by everybody to be dead, but miraculously comes back to life to continue his worldly mission. The Lazarus story may be a nod to this notion, but Paul wanted more. He seems to have had a dispute with Jesus' brother James, who insists that Jesus was a divinely inspired mortal man. This dispute was ultimately decided, under suspicious circumstances, in Paul (and Athanasius') favor at Nicea. I've always suspected that James might have been the older brother although I have no evidence of this.
4Each of these books was individually hand-made. Wood-block printing existed but wasn't used for text until 500 years later, in China. Movable type for printing was devised by Gutenberg 1127 years after Milvia. Some of the purged texts survive as "apocrypha" and a few of the purged groups do too, such as the Gnostics in Egypt. Most are probably lost.
5The most tragic example of this are the repeated sackings of the Library of Alexandria, twice by Romans, in 48BC and 273AD, at least partly by accident, once on purpose by Christians in 391, and again on purpose by Muslims in 642. Ironically, the 273 battle was against Palmyra, some of the ruins of which have been recently destroyed by ISIS/DAESH for exactly the same reason. The suppression of Paganism, the mystery religions, Arianism, Pelagianism, the fates of Hus, Bruno, Galileo and countless rural healers as "Witches". It goes on and on.
Further Reading
http://www.amazon.com/Unriddling-Christian-Origins-Joel-Carmichael/dp/0879759526
http://www.amazon.com/Zealot-Life-Times-Jesus-Nazareth/dp/0812981480
http://www.amazon.com/Jewish-War-Revised-Penguin-Classics/dp/0140444203
https://en.wikipedia.org/wiki/Christ_myth_theory
http://www.salon.com/2015/05/14/the_right_gets_jesus_all_wrong_9_reasons_why_everything_you_know_about_jesus_is_a_myth/
