"The missionary zeal seems rather an expression of some deep misgiving,
 some pressing feeling of insufficiency at the center. Proselytizing is
 more a passionate search for something not yet found than a desire to
 bestow upon the world something we already have. It is a search for a
 final and irrefutable demonstration that our absolute truth is indeed
 the one and only truth. The proselytizing fanatic strengthens his own
 faith by converting others."
               [Eric Hoffer, "The True Believer"]