If two people threaten one another with knives or weapons and one of them kills the other,
what will be their sentence in the world and the Hereafter?
Each of the two people will be guilty of committing one of the major sins since each of them has tried to kill the other. As for the punishment of this sin in the Hereafter, they will both be tortured in the Fire unless Allah (Exalted be He) pardons them or one of them. It was authentically reported that the Prophet (peace be upon him) said:
"'If two Muslims meet each other with their swords, (both) the killer and the killed one are in the Fire.’ It was said, 'O Allah's Messenger! It is all right for the killer, but what about the killed one?' He said, 'The killed one was eager to kill his opponent.'"
(Part No. 21; Page No. 228) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.