The Quran tells us: “whoever killed a human being – except as a punishment for murder or for spreading corruption in the land – shall be regarded as having killed all mankind.” (5:32)

Killing someone is a very heinous act. It is legitimate only if someone becomes a definite danger to social peace. To kill someone without genuine justification is tantamount to the slaughter of the whole of humanity, because such an action is a gross violation of respect for life, which, in turn, leads to the taking of human life becoming a seemingly easy affair.

From the Quranic verse quoted earlier, one can gauge the great importance that Islam gives to peace and security. Islam demands that if a single person is killed, the entire society must react as if it is not a single individual, but, rather, the whole of humanity, that has been slain.

Source: The Ideology of Peace