Complex sentence: Maccoby considered Paul's claims to an orthodox Pharisaic Jewish education to be false, asserting that while many of Paul's writings sound authentic to the uninitiated, they actually betray an ignorance of the original Hebrew scripture and the subtleties of Jewish Law.
Split into simpler sentences: Maccoby considered Paul's claims to an orthodox Pharisaic Jewish education to be false. As his assertions of proof, Maccoby attempted to demonstrate that many statements in Paul's writings betray his ignorance of the original Hebrew scripture and the subtleties of Jewish Law.