I think in the context of executing heretics, it wasn’t really about “saving lives” per se, save perhaps in the spiritual sense. Nobody died from the belief that Jesus was not a part of the trinity, for instance, that is until someone killed them for it.
The name of the gentleman escapes me presently, but I am sure someone can google it.
A few years ago the founder/owner of a file sharing site called MegaUpload was given a sentence of around 125 years for charges pertaining to piracy. Considering one can actually commit murder and receive around 11 years in Western Europe this is quite harsh punishment.
As marcarbe as the logic was behind it while killing someone obviously caused harm, piracy caused harm to the lives/occupations/employment of many thousands of people. Ergo, it deserved a far harsher punishment according to the American legal system than had this gentleman gone out and performed a school shooting.
Heretics of the day were very similar, in that they threatened the fabric of the reality that held the theocracy together. As soon as you doubt the church is the instrument of God, individuals tend to reject its overarching power. We saw this best in the Reformation after all. Heretics threatened the status quo, which was far more valued than the lives of any number of humans.
A modern example is Ireland. Thirty years ago homosexual marriage was unthinkable, indeed homosexual inclinations themselves were illegal until the early 90’s. Once the scandals emerged that made people doubt in the authority of the church, it’s own theocratic control over Irish state simply evaporated overnight, to the extent they now have a homosexual man as their prime minister.
Twenty years ago, you’d probably have been charged with blasphemy and promoting sodomy for suggesting that could even happen (Blasphemy interestingly is still a criminal offense in Ireland, although since the sex scandals hasn’t to my knowledge been enforced wheras prior it was regularly used to promote Catholic interests).
