Typical post-modern scholarly gibberish

It turns out that Christianity was just made up by Jews as they caved under the Roman assault on Jerusalem in 70 A.D.  Yep.  A scholar says so, so it must be true.  Of course, the fact that various early epistles in the New Testament were written before that might cause some trouble.  Still, as with most modern scholarly arguments, we can just wave our hands, dismiss hundreds if not thousands of years of traditional dating of the letters and say they were really all written after 70 A.D.  If modern approaches to historical studies are so free and loose, it does make me wonder about other academic disciplines in other fields of study.