I realize understanding this might be tough for an ESL student, but I'll give it a go anyway. Here's the Vatican's statement:
1. The right to freedom of thought and expression ....cannot imply the right to offend the religious sentiment of believers. This principle applies obviously for any religion.
They're talking about the right to offend the religious sentiments of believers, and they don't believe that right exists. I maintain that it does, as the First Amendment confirms. I said absolutely nothing about the Vatican not having a right so say whatever it wants.
Now hit those books, kid.
However, your having the right to say something, does not equate to what you said being right, or without legal consequences. There are acknowledged limitations to the First Amendment, and you are held liable for the extent of your "critizism" of others and the actions those words incite or intended to incites.
Plenty of case law concerning limitations on free speech available to "scholars" such as yourself.