The recent announcement of the supposed discovery of the ossuaries (bone boxes) of Jesus' family is void of scientific and archaeological merit (Is this really the last resting place of Jesus, Mary Magdalene - and their son?, February 27).

I am both a medical doctor and a doctor of theology, and it is unusual for both of my disciplines to be irked at once. Yet the documentary film-makers behind these claims - to be broadcast on the Discovery Channel - have managed to fail on both scientific and theological grounds simultaneously. As the Guardian report rightly notes: "Even as the felt was being pulled back yesterday, holes in the theory were becoming glaringly evident."

So, for instance, there is a huge leap of logic in moving from the purported DNA evidence that "Jesus" and "Mary" were not maternally related, to the conclusion that they were a couple. A whole range of other familial relationships are possible, even apart from the issue of whether this is in fact the Jesus, and the Mary Magdalene.

The film-makers also fail in their theology. They suggest that their finding does not negate the New Testament claim to the bodily resurrection of Jesus, only that it denies his bodily ascension. In other words, according to Discovery Channel theology, Jesus died, rose again, died again and then rose "spiritually" to be with his Father.

This is theological twaddle that neither the New Testament nor any mainstream Christian denomination affirms. The article labels as "predictable" the response of Christians who have been outraged by this, so let me try a different approach and draw attention to the one useful comment made by the film-makers.

James Cameron, the director of the film Titanic, said in support of the project: "It doesn't get bigger than this." He's right, and this is the real significance of the story, why it made the Guardian's front page, and why the current attempt by some on the left to put religion back in its quaint middle England box can only fail. A story that challenges the resurrection narratives, even if devoid of merit, will always create headlines.

This is not a story that casts doubt on the bodily resurrection of Jesus Christ - there are simply too many problems with the evidence presented - but it is a story about the nature of theological truth claims.

These truths are self-involving narratives. In contrast to most archaeological or historical discoveries, whether Jesus actually rose from the dead or not is an event that one cannot take a dispassionate view on. If he did not rise bodily then, to paraphrase St Paul, the Christian faith is utterly pointless. If he did rise bodily, then this vindicates all that he said, and demands that we acknowledge his Lordship over us.

A neutral stance over the bodily resurrection of Christ is not a fair-minded, rational approach; it is a mark of intellectual and personal cowardice. It is for precisely this reason that Richard Dawkins gets so irate. Even he realises that orthodox Christianity is not something one can be anodyne about.

· Dr Justin Thacker is head of theology of the Evangelical Alliance