I have the Lord Jesus Christ watching over me according to a bunch of folks. If the good Lord says its my time, no amount of firepower will protect me.
Coming from a believer...
In the same vein, we shouldn't use seatbelts. We should get rid of fire extinguishers and smoke alarms. Heck, I think I'll disable the brakes on my car. I mean, if it's my time, it's my time...
Jesus also says:
"...whoever has no sword is to sell his coat and buy one."
If it's my time, it's my time, but if someone wishes to do me or my family harm, they might be coming with me.