While not everything I say is meant to be taken literally, when I said if I were really religious, I wouldn't own a gun, I mean I wouldn't own any guns at all. And I also wouldn't own anything worth stealing either. We apparently have different ideas about religion. Christianity started going downhill when it became legal, followed by when it became required. Anyway, I certainly wouldn't kill someone. It would land me in a lot of legal trouble and probably upset the person's relatives.
Returning to running away, I understand there are laws in some places that require people to retreat when possible. Of course, it's not always possible, such as where I sit now upstairs at home.
I think one's reaction time or lack of, is going to make more difference than anything when something happens. Some people won't react no matter what happens, while others will react almost instantly, like in the incident aboard the French train. So ultimately, it isn't so much about weapons and training, it's about reacting. Curiously, on the train, it wasn't the bad guy who was charging, it was the good guys.