It’s fiction. Nothing that he even proposed in the book is Earth shattering or new. It’s been debunked every which way it could. He based his ideas off an earlier book called “Holy Blood, Holy Grail”, which took long rumors and early speculations that Jesus and Mary Magdalene had been husband and wife, speculations about the Templars settling in Scotland and other stories and put them in a “history” book. (All of this is just a theory, which I think is far fetched and untrue) but those rumors floated around ages ago.
While I didn’t read Brown’s book, I tried, it bored me from the start. I don’t think it should be banned either. I’m a writer and censorship just reeks. In the US, we have freedom of the press, separation of church and state and freedom of speech. While not everything written or spoken is accurate, polite or nice, we have the right to say or write it, whether we like it or not.
It’s not going to shake up the faith nor destroy the Catholic Church. The fact that people are walking away from their faith, (Catholic and other religions) has nothing to do with this book. I’m inferring that by something in the OP. That’s a far fetched notion too. A parent has the responsibility to teach a child his or her faith, that parent must his or her faith by example and show the child what faith is all about. It’s our responsibility as adults and parents to keep our children in the faith. I think often we’re the ones failing them.