In contradistinction to the gospel portrayals of Jesus as a grand, triumphant, and even divine being, the Jesus of history was a rather sordid fellow. That Jesus was an apocalyptic preacher who taught that the world would soon be turned on its head by the arrival of the earthly Kingdom of God. He believed that he was the Messiah, a human military leader whom the ancient Jewish prophets had foretold would overturn the power structures of his day and free the Jews from foreign oppression. As it turned out, however, Jesus was crucified as a common criminal before he ever got a chance to make good on any of these claims. (See The Historical Jesus for a fuller presentation of, and argument for, these points.)
The historical Jesus was therefore an extremely unlikely candidate for the founder of what would later become one of the largest, most celebrated religions in the world. But the Jesus Christ at the center of the religion that bears his name is a mythical figure who hardly resembles his historical namesake. In the fitting words of one New Testament scholar, “Christianity is not so much the religion of Jesus… as the religion about Jesus.”
But how could this monumental shift in memories and perceptions of Jesus have occurred amongst the earliest Christians?
From a strictly historical perspective, we can’t know what prompted some of Jesus’s followers to claim that he had been raised from the dead after his crucifixion. Perhaps some of them saw visions of him, which they took to mean that he was still alive spiritually, if not bodily. Perhaps they simply made it up to avoid having to face the unkind reality of their master’s death. Because of the problem of induction – the fact that we can’t necessarily be sure that any law or pattern in nature holds absolutely with no exceptions, because we don’t have access to the full set of data required to be totally certain of such a claim – it’s technically possible, although obviously extremely unlikely, that Jesus was indeed brought back to life, body and all, as the gospels would later describe.
What we can know, however, is that many of his followers did assert that their executed teacher had come back to life. That was the central doctrine that enabled Christianity to emerge out of what would have otherwise been just another short-lived, inconsequential movement that coalesced around yet another failed apocalyptic prophet.
Paul, the author of the earliest Christian writings we possess today (50-60 AD, a mere two decades or so after Jesus’s death), says in 1 Corinthians 1:23: “But we proclaim Christ crucified, a stumbling block to Jews and foolishness to Gentiles.” Paul admits that “mainstream” Jews thought that the idea that the Messiah had already come, but had been crucified without having restored the sovereignty of the Jewish nation, was absurd. But the early Christians reformulated the concept of the Messiah in the aftermath of Jesus’s death to make the event no longer ridiculous and devastating. It had been God’s plan all along. It brought the end of the age and the arrival of the Kingdom of God one step closer, and now the forces of good had a new and extraordinarily powerful ally on their side: the risen Jesus.
Since Jesus had been taken up to heaven and given such a uniquely exalted position by the God he often spoke of as his “Father,” Jesus became, after his death and in the minds of his followers, the “Son of God.” Furthermore, since Jesus had often spoken of a celestial being called the “Son of Man” who was to come down from heaven when the end of the age arrived, and since Jesus was now in heaven, they assimilated him to the “Son of Man,” too. And since Jesus had been exalted to a privileged position in heaven and above all the earth, he was now the very Lord of heaven and earth himself.
At this point, however, Jesus’s followers didn’t yet insist that he had always been such an entity. They thought that he had been born as a purely human being, albeit a divinely-inspired and divinely-appointed one, and was then exalted to a truly divine status after his death. Today, scholars call this view “adoptionism” – the idea that Jesus was “adopted” by the Father and became his Son, rather than having been his Son from the beginning.
Over the course of the first century, many Christians gradually pushed forward the time at which Jesus was adopted by God, going from his death to his baptism and eventually to his birth. (The New Testament writings bear witness to all of these variations.) But the basic idea remained the same.
The definitive statement of the adoptionist view with Jesus’s death as the moment of “adoption” comes from a very early Christian creed quoted by Paul in another one of his letters (Romans 1:3-4): Jesus,
Who was descended
From the seed of David
According to the flesh,
Who was appointed
Son of God in power
According to the Spirit of holiness by his resurrection from the dead.
The “First Fruits” of the Kingdom of God
The flesh-and-blood, historical Jesus had taught that when the Kingdom of God came, the dead would be raised and, alongside the living, judged by God. Those who were found to be righteous and pious would get to live in the happy Kingdom of God, but those who were found to be wicked and impious would be condemned to eternal torment.
When Jesus’s followers began to proclaim that he had been raised from the dead, the significance would have been clear to anyone who knew much of anything about the apocalyptic Judaism within which Christianity originated: the resurrection of the dead that Jesus and others had prophesied had already begun, with Jesus’s own resurrection as a foretaste. In Paul’s words in 1 Corinthians 15:20, Jesus was the “first fruits” of the resurrection.
Jesus had taught that the Kingdom would come within the lifetime of many of those to whom he was speaking, and now his followers understood that they were right at the cusp of that blessed era. Since Jesus had overcome death itself, one of the mightiest of the forces that thwarted the will of God in this demonic age of the world, Jesus’s followers were that much more convinced that he had indeed been chosen by God to be the Messiah who would banish all evil from the world. The only change from their prior understanding was that now they knew that Jesus would lead the charge not from earth, but from heaven.
To quote Paul yet again, this time from 1 Thessalonians 4:13-18:
But we do not want you to be uninformed, brothers and sisters, about those who have died, so that you may not grieve as others do who have no hope. For since we believe that Jesus died and rose again, even so, through Jesus, God will bring with him those who have died. For this we declare to you by the word of the Lord, that we who are alive, who are left until the coming of the Lord, will by no means precede those who have died. For the Lord himself, with a cry of command, with the archangel’s call and with the sound of God’s trumpet, will descend from heaven, and the dead in Christ will rise first. Then we who are alive, who are left, will be caught up in the clouds together with them to meet the Lord in the air; and so we will be with the Lord forever. Therefore encourage one another with these words.
“He Who Hears My Word Has Passed from Death to Life”
But as years turned into decades, the last of those who had been alive during Jesus’s time died, and the Kingdom of God still hadn’t come. Cognitive dissonance set in amongst the early Christians. Was this not a stinging refutation of everything they had believed?
As an earlier generation of Christians had done with Jesus’s death, however, this newer generation of Christians came up with a solution that, while it may have played fast and loose with the historical facts, greatly enhanced the spiritual power of their fledgling religion.
Whereas the historical Jesus had preached that the Kingdom of God was a physical kingdom that would arrive in the future and encompass the entire earth, Christians began to speak of Jesus as having instead preached that the Kingdom of God was a spiritual kingdom to which one could gain entrance at any time, on an individual basis. Jesus, through his life and death, had opened the gates to that kingdom. The Christians of the period disagreed over the particulars of what one had to do to achieve this individual spiritual salvation, as well as what exactly Jesus had said and done to make this transformation possible, but this idea itself soon became the rule rather than the exception in Christian circles.
To be sure, many of them still believed that Jesus would return to earth to herald the end of the age at some point. But that was no longer the focal point of their religion, and, in fact, it seems to have become at most a secondary concern. They also gave up the idea that the end of the age would come within any particular time frame.
The best examples of this dramatic metamorphosis within early Christianity come from the New Testament gospels. Mark, the earliest of the four to be written (65-70 AD) is the one in which the old apocalyptic view speaks the loudest. In Matthew and Luke, both written between 80 and 85 AD, the old view is still present, but takes a backseat to the newer one. Finally, in John, which dates from 90-95 AD, Jesus proclaims the new perspective thoroughly and exclusively.
(While the gospels were named after Jesus’s first apostles and those who were close to them, the gospels probably weren’t written by them – and in the case of Matthew and John in particular, it’s virtually impossible that their names reflect their authorship. But for the sake of convenience, we’ll sometimes refer to the author of a gospel by the name that’s traditionally affixed to that gospel.)
Consider the Gospel of Luke. In 11:20, Jesus says, “But if it is by the finger of God that I cast out the demons, then the kingdom of God has come to you.” Similarly, in 17:21, Jesus says, “the Kingdom of God is among you.” The entire meaning of the “Kingdom” is thereby radically altered. Rather than something that will come in the future, it’s something that’s already manifest in Jesus’s person and ministry. 
The author of Luke still believed that the end of the age was coming soon – within his own lifetime, in fact – but not during the lifetime of the people to whom Jesus spoke. So he altered Jesus’s prophecies as reported in Mark (which he used as a source) so as to make them plausible for his own time. For example, in Mark 14:62, during Jesus’s trial, the Messiah proclaims to the high priest, “You will see the Son of Man seated at the right hand of power and coming with the clouds of heaven.” But in Luke (22:69), which was written long after the death of that high priest, Jesus instead says to him: “From now on the Son of Man will be seated at the right hand of the power of God,” thus eliminating the timetable that placed the event within the remainder of the high priest’s life.
This tendency was carried much further in the Gospel of John. John wasn’t content with Luke’s delaying of the coming end of the age and arrival of the new one. So he transformed this cataclysmic worldwide change to one that occurs within the individual man or woman, who decides, in the present, whether to be saved by believing in the doctrines that John places on the lips of Jesus, or to be damned by rejecting them. Take, for example, 3:36: “He who believes in the Son has eternal life.” Or 5:24: “He who hears my word and believes him who sent me, has eternal life; he does not come into judgment, but has passed from death to life.” Or 12:31: “Now is the judgment of the world.” Or 3:18: “He who believes in him is not condemned; he who does not believe is condemned already.” Contra Paul, the resurrection happens when one believes in Christ.
Jesus’s original apocalyptic message is preserved only in a couple of marginal, vestigial statements, and John has Jesus go out of his way to speak against that older understanding. In a scene in which a man named Lazarus has died, his sister Mary tries to comfort herself by saying that Lazarus will “be raised on the last day.” But Jesus corrects her: he himself is “the resurrection and the life,” and anyone who places his or her faith in him will be graced with eternal life after bodily death.
“The Word Became Flesh and Lived Among Us”
The Christians of the second half of the first century didn’t just revolutionize their understanding of what Jesus had said. Their beliefs about who Jesus had been underwent a similarly epochal shift. No longer were they satisfied with thinking of Jesus as having been “adopted” as the Son of God after his death or at some point during his life. Now, instead of a human who became divine, they came to see Jesus as having been a divinity who became human. Jesus had always existed with God and as a part of God, and only later allowed himself to be incarnated as a mortal man to save mankind from the ravages of sin and evil.
While the New Testament abounds with passages that attest to this view, the most magnificent and sweeping is the so-called “Prologue” of the Gospel of John (1:1-18):
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things came into being through him, and without him not one thing came into being. What has come into being in him was life, and the life was the light of all people. The light shines in the darkness, and the darkness did not overcome it. … The true light, which enlightens everyone, was coming into the world. He was in the world, and the world came into being through him; yet the world did not know him. He came to what was his own, and his own people did not accept him. But to all who received him, who believed in his name, he gave power to become children of God, who were born, not of blood or of the will of the flesh or of the will of man, but of God. And the Word became flesh and lived among us, and we have seen his glory, the glory as of a father’s only son, full of grace and truth. … From his fullness we have all received, grace upon grace. The law indeed was given through Moses; grace and truth came through Jesus Christ. No one has ever seen God. It is God the only Son, who is close to the Father’s heart, who has made him known.
Here, Jesus is the Logos – translated as “Word” – of God. Logos didn’t mean just any “word;” it was a philosophical term that meant, as the great New Testament scholar Hans Jonas put it, “the abstract concept, the method of theoretical exposition, the reasoned system – one of the greatest discoveries in the history of the human mind.” Jesus, then, is the incarnation of the verbal “exposition” of the supremely intelligent Father and the Father’s will. He is an aspect of God that can in some sense be considered to have its own existence while still remaining part of God. The Logos was present at the creation of the world, and creation was accomplished through it. It spoke, and, as in Genesis, it first created light, and then the rest of the world, through its speech. It’s no wonder that John places so much emphasis on Jesus’s verbal teachings, nor that John’s Jesus has a penchant for expounding those doctrines in long, abstract discourses, almost like an ancient Greek philosopher.
This view of the divine, in which various aspects of God are treated as being semi-distinct and credited with agency in their own right, can be found in both Jewish literature of the period and Greek philosophy, especially Stoicism and Middle Platonism. So Christians had a rich theological environment to draw from as they reformulated their idea of who and what their religion’s central figure had been.
The Rejection of the Law of Moses
Of all of the controversies that rocked and reshaped Christianity during the first century, few were more heated, or more decisive, than the dispute over whether or not Christians were still obligated to observe the Jewish Law that, according to the Hebrew scriptures, was given to the Jews by Moses as part of the sacred covenant between Israel and God.
The outcome of this quarrel was by no means a foregone conclusion. Powerful, influential voices represented both sides. Some of Jesus’s disciples themselves, such as Peter and James, appear to have preached that the Law was still in effect. The Gospel of Matthew has Jesus declare, “For truly I tell you, until heaven and earth pass away, not one letter, not one stroke of a letter, will pass from the law until all is accomplished.”
Paul, however, ardently believed that Christians were no longer bound by the Law. In Galatians 2:11-21, he recounts a time when he rebuked Peter himself over this question, and presented his case that Jesus had rendered the Law obsolete:
We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is justified not by the works of the law but through faith in Jesus Christ. … I have been crucified with Christ; and it is no longer I who live, but it is Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me. I do not nullify the grace of God; for if justification comes through the law, then Christ died for nothing.
In Galatians 3:28, he adds that Christ came for the sake of all people, not just the Jews, which made specifically Jewish traditions irrelevant for Christians: “There is no longer Jew or Greek, there is no longer slave or free, there is no longer male and female; for all of you are one in Christ Jesus.”
In the end, the victory went to Paul’s position, presumably largely because it was much, much easier for non-Jews to convert to Christianity if they didn’t have to abide by the Jewish Law, which mandated circumcision for men and a host of onerous inconveniences in one’s daily life.
The process by which Christianity extricated itself from Judaism was a gradual one. There was no single moment at which this shift occurred. But by the end of the first century, while Christianity was still in many ways different from what we today think of as being Christianity, it had gone far enough beyond its roots as a Jewish sect that it was something that we today would recognize as Christian. No longer was it merely a localized, failed apocalyptic movement; it was now a separate religion with universal aspirations, and one that was capable of addressing timeless existential concerns.
 Ehrman, Bart. 1999. Jesus: Apocalyptic Prophet of the New Millennium. Oxford University Press. p. 230-231.
 Ehrman, Bart, 2014. How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee. HarperOne. p. 174.
 Ibid. p. 213.
 1 Corinthians 1:23, NRSV. https://www.biblegateway.com/passage/?search=1+Corinthians+1%3A23&version=NRSV Accessed on 12-21-2017.
 Ehrman, Bart. 1999. Jesus: Apocalyptic Prophet of the New Millennium. Oxford University Press. p. 236.
 Ibid. p. 233-234.
 Ehrman, Bart, 2014. How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee. HarperOne.
 Ibid. 220-221.
 Ibid. p. 203.
 Ehrman, Bart. 1999. Jesus: Apocalyptic Prophet of the New Millennium. Oxford University Press. p. 233.
 1 Thessalonians 4:13-18, NRSV. https://www.biblegateway.com/passage/?search=1%20Thessalonians+4%3A13-18 Accessed on 12-21-2017.
 Ehrman, Bart. 2004. The New Testament: A Historical Introduction to the Early Christian Writings, Third Edition. Oxford University Press. p. xxxii.
 Ehrman, Bart. 1999. Jesus: Apocalyptic Prophet of the New Millennium. Oxford University Press. p. 41-46.
 Luke 11:20, NRSV. https://www.biblegateway.com/passage/?search=Luke%2011:20 Accessed on 12-22-2017.
 Luke 17:21, NRSV. https://www.biblegateway.com/passage/?search=Luke+17%3A21&version=NRSV Accessed on 12-22-2017.
 Ehrman, Bart. 1999. Jesus: Apocalyptic Prophet of the New Millennium. Oxford University Press. p. 130.
 Ibid. p. 130-131.
 Ibid. p. 131.
 Pétrement, Simone. 1990. A Separate God: The Origins and Teachings of Gnosticism. Translated by Carol Harrison. Harper San Francisco. p. 162-163.
 Ehrman, Bart. 1999. Jesus: Apocalyptic Prophet of the New Millennium. Oxford University Press. p. 131.
 Ehrman, Bart, 2014. How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee. HarperOne.
 John 1:1-18, NRSV. https://www.biblegateway.com/passage/?search=John+1%3A1-18&version=NRSV Accessed on 12-22-2017.
 Jonas, Hans. 2001. The Gnostic Religion: The Message of the Alien God and the Beginnings of Christianity. Beacon Press. p. 21.
 Ehrman, Bart, 2014. How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee. HarperOne. p. 273-274.
 Ibid. p. 274-275.
 Ibid. p. 273.
 See, for example, Galatians 2, Acts 21, and the Ebionite pseudo-Clementine literature discussed in:
Ehrman, Bart. 2003. Lost Christianities: The Battles for Scripture and the Faiths We Never Knew. Oxford University Press. p. 183.
 Matthew 5:18, NRSV. https://www.biblegateway.com/passage/?search=Matthew+5%3A18&version=NRSV Accessed on 12-23-2017.
 Galatians 2:11-21, NRSV. https://www.biblegateway.com/passage/?search=Galatians+2&version=NRSV Accessed on 12-20-2017.
 Galatians 3:28, NRSV. https://www.biblegateway.com/passage/?search=Galatians+3&version=NRSV Accessed on 12-20-2017.
 Burns, Dylan M. 2014. Apocalypse of the Alien God: Platonism and the Exile of Sethian Gnosticism. University of Pennsylvania Press. p. 34.