Tyranny and Oppression
Tyranny and oppression are among the greatest sins because they oppose justice, upon which the heavens and the earth were established. Allah ~ sent His Messengers and Books in order that people might establish justice among themselves. The act of killing unlawfully, without any right, is a great sin. Islam cites many examples of such evil acts, like the killing of one's child for fear that the child might share one's provision (i.e. food, drink, and money); the killing of one's parents who were the cause of one's existence; the killing of one's kin. The grade of such an evil act differs according to the nature of the act itself; therefore, the person who will receive the utmost punishment on the Day of Resurrection is the one who killed a prophet, followed by the one who killed an Imam, or a scholar who commanded justice among people and invited them to the Path of Allah ~- Allah ~ has set the punishment for the intentional killing of a believer as dwelling eternally in the Hell-Fire, with the Curse and Anger of the Lord.