~Sorta cute but, still begs a couple Big issues - not merely re the Catholic variants and their antagonists. Issues -

1) As to "effects of the countless duelling religio sects, contemporary and historical" - and the putatve effect their duelling has, in catalyzing the nuts within each one's Gaussian: to Act Violently to suppress / eliminate heretics / opposition / even Moderation itself.

2) More particularly: the tendency of a great many of these extant sects to use the phrase ... to believe the phrase ... thence to Believe!
[some variation of]

*MINE* (Ours!) is The One Truth, Set-in-Concrete For All Time ..and also, BTW -
[And, I assert that this most often: Is taken as inseparable corollary]

- all Others are not merely less-true or less-True: They. Are. Wrong.

I might add a 3) but it's too much work. It would be about the ignorant-hubris thus sanctimony of so much of what passes for 'religion' in 'the West' + the tolerated Delight in that ignorance of so much else that has been discovered:

all as manifest in the sorts of barely-religio- smarminess of the Usual Tee Vee suspects; then the rampant Godliness-on-sleeve of the present Trotskyites and their oozing Judgmental Righteousness cha cha cha

But I won't go into that. The first two shall have to suffice ;-)