That is a very hard question that every person has to ask of them self, even the folks who have served in uniform have to ask this question [not every person who served, can pull a trigger on a another person]. But when you & your family are faced with imminent danger you’ll do what ever it takes to keep yourself & them safe.
One thing I have never heard of in the context of prepping is devotionals.
What? That God stuff?! Nobody has time for God in the middle of SHTF!!