As a fellow Catholic, I passionately disagree, for example, with abortion. I may personally be in no doubt that my beliefs here equate to the ‘Truth.’ However, if I then elect to express such opinions by screaming insults and threats at some young girl who I believe has had, or may be considering having, an abortion, I’m not only failing to further my opinions effectively. I’ve left the path of ‘Truth’ and am misrepresenting and contradicting it.
Leaving the path of truth is always wrong, regardless of the zeal with which it is done. Again, error is the problem, not zeal.
My point is that zeal, or an excess of zeal, can itself cause one to leave the path of ‘Truth’. Where ‘zeal’ manifests itself (as here) to the exclusion of basic human compassion and understanding, as a rejection of the freedom, dignity and beliefs of others, it in and of itself (like most things, when taken to extremes) becomes error, regardless of the nature or validity of the beliefs producing it.
I accept, of course, that the very definition of ‘zeal’ is a subjective one. But then, as previously mentioned, so is the nature of truth. Given that we do not, and never will, all share the same understanding of ‘truth’, there must of necessity be limits imposed to the ‘zeal’ with which any individual can promote his own version of it.
Such limits in no way have to equate to a lack of passion. Strength of belief and passion for a principle are generally good things, but not in themselves incompatible with consideration, respect, tolerance and human decency. It’s when held to the exclusion of these, however, that they become ‘zealotry’ and thus potentially dangerous.