Star Trek: The Original The Weight Of Worlds

Kirk and the Enterprise crew face off against an ancient extra-terrestrial cult known as the Crusade, who believe that ancient prophecies proclaim the universe will soon be destroyed and recreated, but only those who surrender to the Truth will be saved. The Crusade is on a sacred mission to bring the Truth to Kirk's universe before the End comes. But how do you fight an idea? And is the Crusade here to save or subjugate the Federation?