Amid the commercial excesses of the festive season, it's sometimes overlooked why we celebrate Christmas at all.

The birth date of Jesus Christ is one of the most important celebrations in Christianity.

But did the man responsible for the world's largest religion actually exist?

Historians, theologians and secular scholars are agreed on one thing: he probably did. But beyond that basic statement - that a man called Jesus did once walk the Earth - they are divided.

To what extent his life has been exaggerated, mythologised and bent will almost always be impossible to prove.

This in-depth literature review by Alternet's Valerie Tarico outlines five reasons scholars give that he did not exist:

There is no first century secular evidence that he existed - all sources are either Christian or Jewish

The earliest New Testament writings are vague on details of his life - they become more fleshed out in later texts

The eyewitness accounts in the four canonical gospels (Matthew, Mark, Luke and John) are all second hand

The gospels make contradictions about his life

Modern scholars who claim to have uncovered the 'real Jesus' contradict each other

Furthermore, Raphael Lataster, a lecturer in religious studies at the University of Sydney, explained in an article for the Washington Post:

The earliest sources only reference the clearly fictional Christ of Faith. These early sources, compiled decades after the alleged events, all stem from Christian authors eager to promote Christianity – which gives us reason to question them.

Bart Ehrman, the author of Did Jesus Exist? The Historical Argument for Jesus of Nazareth, argues that Jesus' fallibility is good reason for his existence.

The Messiah was supposed to overthrow the enemies – and so if you're going to make up a messiah, you'd make up a powerful messiah. You wouldn't make up somebody who was humiliated, tortured and the killed by the enemies.

Unhandled component type: related