I don't question his intelligence, but I question the premise that his 'strong language' gives any legitimacy to his rants. His consistent use foul language and abuse alone betrays him as one who belongs to the enemy:
But now you must get rid of all such things—anger, wrath, malice, slander, and abusivelanguage from your mouth.
There are several such warnings in the NT, but he seems to think he is exempted from the need to live by them. His own words condemn him.