Thoughts on the whole Da Vinci Code business:
First of all, the movie could have been better, could have been worse, better than expected based on the critics. If you can wait that long, it's a good rental. Ian McKellan is fantastic in it. The book is a great fun read but not as good as a Harry Potter, also the puzzles in Harry Potter are harder to figure out.
As for the premise and all that... as it's been pointed out in a million places, including the court of law, much of it is based on the non-fiction research and speculation book Holy Blood Holy Grail. This is where all the stuff about the Priory of Sion comes from. The chapters on the P.S. in HBHG are really very fascinating! Trouble is, it's quite likely to be a hoax. Here's an article debunking it a bit, although I am always wary of anything like this that claims to have "the truth". The truth is that we can't know the truth, it's impossible to determine what is really "the truth". There is much more than just the Priory of Sion in the the book. It's a good read, especially if you love a mystery. Even if the P.S. is not real, the Templars and Freemasons certainly were (are), and the Bible has been tailored by the Church to suit the Church. Why that was done is going to be controversial.
My take on the main punch line of both of these books is this. I was raised as a Christian, but no longer believe in Jesus' divinity... or the divinity of anything for that matter. Gods are where you want them to be. To me, if Jesus even existed, he was a wise man and powerful leader but nothing more. Was he married to Mary Magdalene? I think it's very plausible. Could he possible have faked his own death and escaped? Don't laugh. If you are a Christian, then your own beliefs are far more bizarre than that if you can look at them objectively for even a moment. I'm not saying I believe these things. I have already stated my beliefs and disbeliefs. I am saying that I think either of these things could have happened. We just don't know. Can't prove anything one way or the other.
Jesus and MM both had kingly blood and their offspring would have had to be kept in hiding or surely be killed given the politics of the day (the same might be true today). Nowadays though, the only thing with real power is just the possible existence of that bloodline, and that wields the power to diminish the Christian church. So if the bloodline exists, why not reveal it? If there's paperwork, let's see it. I call. Show your hand or fold. Exactly what are you waiting for? I can't think of a better time to show your stuff.