I am not denying that it is good to love others, especially a sister, however Matthew 10:37 tells us that we must love God/Jesus more. 37: “Anyone who loves their father or mother more than me is not worthy of me; anyone who loves their son or daughter more than me is not worthy of me. Furthermore, we are instructed not to do evil to bring about something good. Romans 3:8 Why not say—as some slanderously claim that we say—“Let us do evil that good may result”? Their condemnation is just!To kill someone to save ourselves or another, even a loved one, is doing evil to achieve something we perceive as good. God will not let anyone die or be punished that He hasn't planned for it to happen to. You need to have the faith in His power, to believe that. If you can't believe that God created the universe in 6 days then I don't know if you would believe that He has the power to protect anyone He wishes to. If you do believe in the 6 day creation narrative and the power necessary for it, then this belief should be easy. Good does come out of death, mutilation and torture, even if we can't see it with our worldly eyes.