If many of the facts in The Da Vinci Code don't stand up to scrutiny, then is Dan Brown a liar?

That would be a tough call to make of a novelist, whose profession is all about making up stories!

But where The Da Vinci Code is perhaps a bit unfair with its readers is in blurring the line between fact and fiction. We human beings like to know whether we are reading something that tells us about events that happened in reality, or in someone's imagination. We like reading both history and fiction, but we like to be sure which is which.

When a book is published as a memoir or a history, and then is later discovered to be a fake, there is always a huge media fuss, lots of complaining and usually some suing. We really do care whether we are being tricked into believing something that isn't 'for real'.

So when Dan Brown opens his novel with a page headed 'FACT', we expect to be able to rely on it. The fact is that of the three facts listed on that page, only one deserves that description. Yes, there is a devout Roman Catholic group called Opus Dei and they have a large headquarters in New York City. However, the other two facts-one, that there exists an ancient secret society called the Priory of Sion with members such as Leonardo da Vinci and Sir Isaac Newton; and two, that "all descriptions of artwork, architecture, documents and secret rituals in this novel are accurate"-are both false and we can prove it.

For more on the hoax that is the Priory of Sion, click here.

The claim to accuracy is the most disturbing one. Dan Brown really set himself up for a fall here, because experts the world over have been pointing out where he went wrong in his descriptions of the streets of Paris, the pyramid outside the Louvre, the interpretations of Leonardo da Vinci's paintings, and most significantly, his claims about the Bible and Christian history.

Here are just a few of the claims of the novel about Christianity that can't possibly be true:

* "The Bible was stitched together by Emperor Constantine". But it was already together before Constantine came along.

* "There were many other accounts of Jesus' life that were left out of the Bible". The truth is that we only know of a cluster of bits and pieces of other documents about Jesus. The best material is in the Bible itself.

* "Jesus was declared divine by a narrow vote at the Council of Nicea." No, he was considered divine from the earliest days and declared divine at the council by 298 votes to 2!

On his website (danbrown.com), the author is upfront about his reasons for writing The Da Vinci Code. He says, "My hope in writing this novel was that the story would serve as a catalyst and a springboard for people to discuss the important topics of faith, religion, and history".

Dan Brown was doing more than entertaining us. He wants us to think about religion and what is worth believing. This means we need to look very seriously at what his characters claim to be fact, and see if it measures up. Most experts think that very little of what Dan Brown's novel calls 'fact' really is fact. We have to ask ourselves: is it worth believing? And if not, what is the truth about Jesus?