Getting to Know Allah
Is there a better way of getting a handle on what type of god you're dealing with than getting acquainted with what it considers a damnable offence. Allah's list of sins which will get you an invite to an eternity burning in Hell is lengthy by the standards by which such list are measured, with the Ten Commandments at the more succinct end.
The Greater Sins (or Grave Sins) are those where the Koran, or a saying of the Prophet explicitly state, or imply that those who commit these sins will go to Hell; or where there is a consensus among Islamic scholars that the sinner is going to Hell. It does not matter if the sin is committed in secret.
6:120 Avoid open and secret sins. Surely those who commit sin shall be punished for what they have perpetrated.
Indecency and unwarranted aggression are sins, the following revelation setting them apart notwithstanding.
7:33 Say: “My Lord has only forbidden open and secret indecencies, sin, unjust aggression, and your association with Allah that for which He sent down no authority, and your saying about Allah that which you do not know.”
You need not worry about small indecencies.
53:31 And to Allah belongs whatever is in the heavens and on the earth, that He may reward the evildoers for what they did, and reward the righteous with the fairest reward;
53:32 Those who avoid grave sins and foul acts, except for venial ones. Your Lord’s forgiveness is indeed ample. He knows you very well since He produced you from earth, and while you were still embryos in your mothers’ wombs. Do not commend yourselves, He knows very well who is the God-fearing.
The importance of knowing the difference between an evil deed and a grave sin cannot be overstated!
4:31 If you avoid the grave sins you are forbidden, We will remit your evil deeds and let you enter into an honourable place (Paradise).
Your "evil deeds" will be forgiven if they were committed out of ignorance and when it became clear to you that what you did was evil, you repented immediately and not because you were threatened with death or on your death bed. Unbelievers, however, can repent all they want, it won't do them any good.
4:17 Allah has taken upon Himself to accept the repentance of those who commit evil in ignorance and then repent immediately after that. Those, He will forgive and Allah is All Knowing, Wise.
4:18 But not the repentance of those who commit evil deeds, and when one of them is faced with death, he says: “Now I repent”; nor the repentance of those who die as unbelievers. For these, we have prepared a very painful punishment!
The Greatest Sin of All
Considering Allah relentless invectives against would-be competitors it should come as no surprise that worshipping other gods is the greatest sin of all and for which men, women and children have been slaughtered in their tens of millions with Indians the most unfortunate, the murdered estimated at 70 million (K. S. Lal, Growth of Muslim Population in Medieval India, 1973).
17:39 That is part of what your Lord has revealed to you of wisdom. Do not set up with Allah another god, or else you will be cast in Hell, despised and rejected.
22:12 He calls, besides Allah, on that which neither harms nor profit him (other gods). That is the worst (the farthest from the Way) error.
22:13 He calls upon him whose harm is likelier than his profit. Wretched is the Master and wretched is the ally!
The Top 50
17:38 The evil of all this is hateful in the sight of your Lord.
Greater Sins in Descending Order of Evilness
1. Shirk (polytheism), associating other gods with Allah.
2. Yās (despair), to doubt Allah’s Mercy.
3. Qunut (despondence), losing hope in Allah.
4. Not fearing Allah’s punishment.
5. Murder (of a believer, with some exceptions).
6. Parental disobedience.
7. Breaking up with relatives.
8. Usurping the property of orphans.
9. The charging of interest on borrowed money.
10. Fornication (adultery).
12. Wrongfully accusing a chaste believer of adultery or homosexuality.
13. Drinking alcoholic beverages
15. To neglect an obligatory religious duty.
16. Playing musical instruments or listening to music.
19. False oaths.
20. False testimony.
21. Concealing evidence.
22. Breaking a promise.
23. Misappropriation of property.
25. Short weighing or cheating in business.
26. Eating of what is unlawful.
27. Usurping the rights of others.
28. Avoiding Jihad.
29. Becoming A’Arāb after Hijrat, “the condition when a desert Bedouin before acquiring the necessary knowledge of religion turns back to his ignorant ways.”
30. Helping the oppressors.
31. Not helping the oppressed.
33. Extravagance e.g. wasteful expenditures.
35. To war against Muslims.
36. Eating of carrion, pork and blood.
37. Omitting prayer intentionally.
38. Non–payment of Zakat (obligatory charity).
39. To consider the Hajj (mandatory pilgrimage) insignificant.
40. Persistence in minor sins (committing a lesser sin repeatedly).
10 Deduced Sins
Greater Sins for which there is no explicit verse or saying of the Prophet damning the sinner to an eternity roasting in Hell.
42. Telling tales.
43. Insulting a believer.
44. Intrigue, deception and breaking covenants.
45. Hoarding and selling on the black-market.
46. Disrespect of the Qur’an.
47. Disrespect of Ka’ba.
48. Disrespect to Masajid (mosque).
49. Disrespect of the Tomb of the Prophet.
50. Disrespect to the soil of Imam Husain’s Grave (Shia Islam).