Is it a sin to kill in self-defense?
(From the Bible)
The Bible does not require us to passively endure attacks from assailants. If someone breaks into our home or threatens our lives, we have a biblical and legal right to defend ourselves with deadly force if needed.
"If a thief is caught in the act of breaking into a house and is killed in the process, the person who killed the thief is not guilty" (Exodus 22:2 NLT).
What makes killing in self-defense allowable in the view of the law and the Bible is the reality that you are actually defending your own life against attack. It normally takes a jury to figure out whether you were the aggressor or shared in initiating the deadly conflict.
(From the Quran)
…Take not life, which Allah hath made sacred, except by way of justice and law. (Al-An`am 6:151)
[(From the Sunnah) teachings of Prophet Muhammad S.A.W.]
It is reported that a man came to the Messenger of Allah (peace and blessings be upon him) and asked, "O Messenger of Allah! What should I do if someone comes to me with the intention of taking my property?'' He replied, "Do not hand it over to him.'' The man further asked, "What should I do if he fights me?'' The Messenger of Allah answered , "Then fight him.'' "What would be my position in the Hereafter if he killed me?'' The Messenger of Allah replied, "In that case you are a martyr.'' The man asked: "What if I killed him?'' The Messenger of Allah replied, “He will be in the Hell-fire.” (Reported by Muslim)