Just read about this - it's reported the attacker was using a shotgun.
Compare Sutherland Springs. Still in Texas, still a church, still brought down by a carrying civilian - but he had an AR-15 clone and killed dozens before he was stopped.
Picked it because it's the closest to "all else held equal" in terms of circumstance, so as to minimise confounding variables.
I have no information either way. Per media reports, the guys who brought down the White Settlement attacker were church security; it seems plausible that pure-civilians don't usually worship while armed. On the other hand, it would also be believable that the Sutherland Springs shooter did face armed resistance but prevailed against them.
@khird WEll in the end anecdotal evidence only goes so far, thats as much true for my OP as it is for your rebuttal.
But in the end the truth is, we know fromt he data that when you make guns illegal homicide almost always spikes in the decade+ that follows, when guns are made legal again it tends to shoot back down. This is true in almost every case when we look at the data, so in the end that is the only deciding factor for me. Anecdotal evidence is more for the people who arent good with proper statistical data like that.