CLAIM: Catholic belief is unscriptural.
This is true. During every Mass, there are two readings from the Old Testament and two from the New Testament, including (always) a Psalm and a reading from one of the Gospels. But this is all for show. In fact, Catholics are forbidden from reading the Bible. The only Catholic who is allowed to own a Bible is the pope, and he won't tell the rest of us what it says.
His post about The Da Vinci Code is also not to be missed. (For me, ridiculing that book and movie is something of a hobby.)