Where to start with The Lost Symbol… It was terrible!! Life is too short to read books like this. 
To summarize why it is bad: flat stereo typed characters, a plot that was hard to care about, a ridiculous “reveal” at the end that isn’t worth waiting for, I could go on and on.
Where The Da Vinci Code made claims that Jesus was married to Mary Magdalene, the basis of Symbol’s mythology is that the human mind is capable of changing matter, and that this fact is actually the main point of the Bible. Interesting, but if that is your cup of tea read The Secret. Similar idea, but slightly more interesting and without all the bad characters.