Easter is now upon us, and we await the predictable onslaught of naysayers who declaim with an almost evangelical fervour that the Jesus story is one big lie. Such tirades by the evangelists of scepticism seem almost to constitute a pastoral responsibility on their part annually to reinforce the ideological conceits of their tribe of followers, thus providing atheists, agnostics and "nones" with reassurance that they needn't take Jesus too seriously.

The opening salvo this year comes courtesy of the indefatigable Bart Ehrman. For those who don't know, Ehrman is something of a celebrity sceptic in the United States. A professor of religion at the University of North Carolina, he was formerly a fundamentalist Christian who de-converted to agnosticism, and now writes books exposing the apparently fallacious claims of traditional Christianity. He has several New York Times best-sellers to his name, including Misquoting Jesus: The Story of Who Changed the Bible and Why, Jesus Interrupted: Revealing the Hidden Contradictions in the Bible and Forged: Why the Bible's Authors Are Not Who We Think They Are. Ehrman is a regular on the talk-show circuit, frequenting programs like The Colbert Report, The Daily Show, Dateline, CNN, and National Public Radio.

A genuinely erudite scholar of ancient texts and a fierce debater, Ehrman is the bane of traditionalists and the champion of sceptics. A pity, then, that he is almost always wrong.

Late last year, while attending a large biblical studies conference in Baltimore, I was navigating the maze of bookstalls and I noticed a huge billboard promoting Ehrman's latest effort: How Jesus Became God: The Exaltation of a Jewish Preacher from Galilee . It wasn't difficult to anticipate what is by now an utterly predictable narrative. Jesus was not God. He did not think he was God. The myth about Jesus being divine was later invented and got codified at the behest of the Roman Emperor Constantine at the Council of Nicea in 325 CE. In many variations of this narrative - thankfully, Ehrman's is not one of them - Constantine, who converted to Christianity around 312 CE, wanted Jesus "made" divine so he could use Christianity as propaganda to keep his empire together: one emperor, one state, one God. As popular as this narrative remains, it is has one fatal flaw - namely, it is demonstrably false.

Several friends and I thought it might be useful to come up with an immediate response to Ehrman and, in so doing, provide a more historically accurate account of how belief about Jesus as a divine figure emerged in the early church. Thanks to the generosity of HarperOne, my colleagues and I read a pre-publication copy of Ehrman's manuscript over the Christmas break and wrote up our own account about the when, where, how and who of the origins of belief in Jesus as God: How God Became Jesus: The Real Origin of Belief in Jesus's Divine Nature .

According to Ehrman, the notion of "divinity" in the ancient world was plastic rather than absolute. Greco-Roman gods like Zeus became human, and humans like Alexander the Great and Julius Caesar were venerated as gods after their deaths. Jesus could then be placed on a spectrum of divinity, and could be regarded as "divine" either in the sense of a heavenly figure who became human (incarnation) or a human who was exalted to heavenly status (exaltation). Ehrman regards this as far more probable, since he contends that Jesus did not think he was God, but was simply an apocalyptic prophet earnestly awaiting the end of the world. Jesus died - without burial, Ehrman adds - and it was belief in Jesus's resurrection that led his followers to think of him as divine - but, again, not divine in an absolute sense. It was only later, with writings like the Gospel of John and the incrementally increasing veneration of Jesus in subsequent centuries, that Jesus came to be thought of as equal to God.

Now, not everything in Ehrman's account is wrong. For example, Ehrman rightly explodes the popular caricature that Jesus walked around Palestine saying, "Hi, I'm God, second person of the Trinity, and soon I'm going to die for your sins. But first let me tell you some good stories that you can pass on to your children." There is no doubt that it took the church time to find the best language, grammar, categories and scriptural texts to explain who Jesus really was . Indeed, the question of "who is Jesus" proved to be a messy one, even divisive, exciting internal debates as much as external mockery from pagan critics. It took considerable time for a consensus to emerge in the early church about how Jesus was related to the Father and how Jesus's divine and human natures related to each other.

These debates, however, were largely footnotes and appendices to a high view of Jesus's person that emerged very early on. It is no exaggeration to say that, within twenty years of his death, Jesus's followers regarded him as a pre-existent being who became human, achieved a redemptive task by his death and resurrection, and was exalted to the right hand of God the Father. They also believed that the God of creation, the God of Israel, was now to be known in, through, and even as the Lord Jesus Christ. In other words, for the early church, Jesus redefined the very meaning of God.

But while Ehrman insists that there was a continuum of between gods and humans in the ancient world, I contend that Jews and Christians held to a strict monotheism that delineated God from the rest of the created order. And when they mapped out where Jesus belonged on this ledger, he was clearly on the God-side - not semi-divine or quasi-divine, but identified with the God of creation and covenant.

And whereas Ehrman thinks that Jesus was a prophet who proclaimed God's judgment of this world, I argue that the historical Jesus saw himself as proclaiming and even embodying God's kingship. Jesus believed that, in his own person, Israel's God was becoming King, which is why Jesus spoke and acted with a sense of unmediated divine authority, why he identified himself with God's activity in the world, why he believed that in his own person Israel's God was returning to Zion as the prophets had promised, and why he outrageously claimed that he would sit on God's own throne.

Whereas Ehrman claims that Jesus was very probably not buried, Craig Evans engages in a devastating refutation by bringing together ancient sources and archaeological evidence to show that it was the norm, not the exception, for Jewish victims of crucifixion to be buried. Ehrman's account of the burial story of Jesus cherry picks the evidence, and even misrepresents it. The burial story has a bedrock of historical evidence for what happened to Jesus's body after his crucifixion.

Whereas Ehrman asserts that the early church ebbed and flowed in its beliefs about Jesus from a man exalted to heaven, to an angel who became human, to a pre-existent "divine" person who became incarnate, to a subordinated god, to being declared one with God Almighty; in contrast, Simon Gathercole and Chris Tilling show that many of these assertions do not stand up to scrutiny. Instead, they contend, biblical authors are remarkably consistent in their identification of Jesus with the God of Israel.

Whereas Ehrman likes to point out the ad hoc and adversarial context in which beliefs about Jesus evolved in the course of the first four centuries of the Christian era, Charles Hill demonstrates the remarkable coherence of "orthodox" views of Jesus and their rootedness in the New Testament. Hill shows that what became Christian "dogma" about Jesus was not merely a knee-jerk reaction to various debates going on inside the church.

So despite the fact that Ehrman's book is genuinely informative in places, my co-authors and I think he gets many things wrong - seriously wrong. Yet there is no doubt that many people will lap up the book because of its putative "insider" perspective. Ehrman describes how he once believed that Jesus was God and later came to have a very human and even low view of Jesus. He gives readers the inside scoop on the historical problems and theological paradoxes that traditionalist Christians hope you never discover.

Although Ehrman claims that he is simply not interested in whether Jesus really is God, preferring to limit himself to the matter of history, I suspect otherwise. Ehrman, implicitly at least, is an evangelist for unbelief, enabling sceptics to keep their disgust with Christianity fresh, while trying to persuade believers that their cherished beliefs about Jesus are a house of historical straw.

For all of his failings, Ehrman has at least done Christians one favour. He has challenged us to ask afresh, "Who is Jesus?" While some will say "legend," some will say "prophet," some will say "rabbi." There will be still others who, like Thomas leaving his doubt behind when he encountered the resurrected Jesus, and could not but exclaim, "My Lord and my God!"

Michael Bird is a Lecturer in Theology at Ridley Melbourne College of Mission and Ministry and a fellow of the Centre for Public Christianity. .