Someone here (I won't mention the name) said we need to have faith in God to protect us.
I would risk my salvation to kill someone while defending an innocent person because of my faith in God.
Faith? Hmm I think that might be a little faith.
Well, rest assured your sins are covered if you're in Christ.
The person you speak of reminds of the guy that wouldn't let himself be rescued in a flood. He refused to get in a boat that came for him and refused to climb in a helicopter that came for him. When he drowned and went to heaven, he asked God, "why didn't you save me!!" God said, "What do you mean, I sent a boat and helicopter."
God's not always going to save us, but he gave us the proverbs and lot of good advise in scripture to preserve our lives. And Christ specifically commanded us to spend money on weapons, even if it meant selling some of our clothes.
And amen on the sovereignty.