Al-Munajjid considers the degree of sin involved in killing a non-Muslim vs. killing a Muslim

Fatwa, posted 4.22.2010, from Saudi Arabia, in:
Religious Authority: 
Muhammad Saalih al-Munajjid
Fatwa Question or Essay Title: 
Considerations of the degree of sin involved in killing a non-Muslim vs. killing a Muslim:
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Islam Question and Answer

[Question: I've read that in Islam it is a greater sin to kill a Muslim than a non-Muslim. However, on death a Muslim will be in Paradise whereas the non-Muslim will be in Hell.To kill a non-Muslim is to deny them forever the chance of becoming a Muslim, and condemns them to Hell. Is this not then a greater sin?]

Killing a non-Muslim when he is a muaahid (one of those who have a peace treaty with the Muslims) is a sin, one of the major sins. Al-Bukhaari narrated that Abd-Allah ibn Amr ibn al-Aas said:

“The Prophet said: Whoever kills a muaahid will not smell the fragrance of Paradise, even though its fragrance may detected from a distance of forty days.’” But with regard to non-Muslims who are at war with the Muslims and do not have a peace treaty with the Muslims or are not living under Muslim rule, then Muslims are commanded to kill them, because Allah says (interpretation of the meaning):“Fight those of the disbelievers who are close to you, and let them find harshness in you” [al-Tawbah 9:123]

But this should be in the case of jihad under the leadership of one of the leaders of the Muslims, or his deputy.

[Note: To access a range of opinions on this topic, see the keywords: jihad, war.]