In Islam, the protection of one soul from being killed may be equal to giving life to all humankind; likewise, the killing of an innocent soul may be equal to the killing of the entire human race.
Allah Almighty says: "For that cause We decreed for the Children of Israel that whosoever killeth a human being for other than man slaughter or corruption in the earth, it shall be as if he had killed all mankind, and whoso saveth the life of one, it shall be as if he had saved the life of all mankind. Our messengers came unto them of old with clear proofs (of Allah's sovereignty), but afterwards lo! many of them became prodigals in the earth." (Al-Ma’idah: 32)

Islam is against oppression and injustice and killing innocent people, whether they are Muslims or non-Muslims. This fact is declared in the Qur’an when Allah says: "Allah commands justice, the doing of good, and liberality to kith and kin, and He forbids all shameful deeds, and injustice and rebellion: He instructs you, that ye may receive admonition." (An-Nahl: 90)