[Da Vinci Code] How would the big "secret" really affect the world if revealed?
The big reveal in The Da Vinci Code is twofold:
- Jesus Christ was married to Mary Magdalene, and their children became the Merovingian kings.
- Mary Magdalene is buried underneath the Louvre pyramid.
The first is already widely known in-universe before the novel starts. Robert Langdon knows the secret from page 1. He's made documentaries about it with Teabing. It's not yet accepted by historians, but it's not by any means a secret.
The second part is the only real discovery of the book. But let's assume the Priory went public and revealed Mary Magdalene's bones to the world. What would it prove?
DNA could show it was an ancient Judean woman, but not who. It would be very difficult to authenticate these bones as the real Mary Magdalene - it could be any lady from first-century Judea.
And the Jesus bloodline? That would be impossible to prove. We have no DNA of Jesus. Heck, we've never even extracted Merovingian DNA from any of their bodies. The most you could ever prove was that this first century Judean woman was the ancestor of Sophie Neveu.
Even if the Priory has ancient documents asserting a marriage, they would be no more definitive than any ancient apocryphal gospel.
So in reality, if the Priory went public, the Catholic Church would rejoice! Bones of Saint Mary Magdalene! No genetic proof of a Jesus bloodline. And the fact that the Priory does NOT have the bones of Jesus would only strengthen the Church's case!