Suicide

If a Muslim is afflicted with a calamity and shows patience and seeks Allah's pleasure in that, this calamity will increase his rewards. But if the Muslim gives up (of Allah's mercy) and feels unsatisfied with his life and thinks that the best way to get rid of his problems and agonies is to commit suicide, in that case he chose disobedience and incurred Allah's anger on himself and killed his own self without just cause. Bukhari narrated that Abu Hurairah (may Allah be pleased with him) said: The Prophet (Peace be upon him) said:

 “He who commits suicide by throttling shall keep on throttling in the Hell-Fire (forever) and he who commits suicide by stabbing himself shall keep on stabbing himself in the Hell-Fire (forever).” [Reported by Bukhari (3/180)].

Bukhari and Muslim, may Allah have mercy on them both, narrated that Abu Hurairah (may Allah be pleased with him) said:

"A man witnessed the battle of Khaibar with the Prophet (Peace be upon him), and he (Peace be upon him) said about a man claiming to be a Muslim: "This (man) is from the dwellers of Hell-Fire." When the battle began, the man [whom the Prophet (Peace be upon him) talked about strove satisfactorily and he was wounded badly. Then it was said to the Prophet (Peace be upon him): "The man you talked about earlier strove in the battle satisfactorily and died (isn't he a martyr?)." The Prophet (Peace be upon him) said: "To Hell-Fire (he shall go)."

Doubt sneaked to the hearts of the Muslims. While being in such a state, it was said that the man did not actually die but wounded badly. When night came, the man could not bear the pains and killed himself (i.e. committed suicide). The Prophet (Peace be upon him) was told the matter and then he (Peace be upon him) said: "I bear witness that I am Allah's Slave and Messenger." Then he (Peace be upon him) ordered Bilal (may Allah be pleased with him) to announce for people that: "None will enter Paradise but a believer. And verily, Allah may support this religion (Islam) with a wicked (sinful) man." [Bukhari narration (6/125) and Muslim (111)]