If I were captured by a gang of Muslims who'd tell me "Convert to Islam or die", there wouldn't be anything I could do to stop them. All I could do is die testifying FOR, not against, Jesus.
OTOH, if someone broke into my home, I would be sure it wasn't a Fuller Brush salesman, & if I saw he/she had a weapon, I'd bust some caps on 'em from my own weapon. If he/she were unarmed, chances are that, despite my age, I'm an experienced fighter & some 220 LB. & I could likely subdue 'em. If, however, an invader were to grab my wife, I'd certainly fatally shoot'em without question.