• Great Shirk: worshipping beings other than Allah (proof all over Quran)
• Small Shirk: Riya

The Prophet (PBUH), "Should I not inform you of that which I fear for you even more than the dangers of Dajjal? It is the hidden shirk: A person stands to pray and he beautifies his prayer because he sees the people looking at him". (Sahih; Sunan ibn Majah)

2. Committing murder: (Furqan; 68)

3. Performing Sorcery (2: 102)

4. Not performing the Prayers (Maryam: 59)

5. Withholding the Zakat (Charity) (3: 180)

6. Breaking the fast of Ramadhan or not fasting in that month without a valid excuse.

Prophet (PBUH) said, "Islam is built upon five pillars: testifying that there is no true god except Allah and that Muhammad is the messenger of Allah, performing the prayers, paying the zakat, making the pilgrimage to the house, and fasting the month of Ramadhan" (Sahih al-Jami # 2837)

7. Not performing the pilgrimage when one has the ability to do so (above hadith)

8. Disobeying one's parents (al-Isra: 23)

9. Cutting off the ties of relationships (Muhammad: 22)

10. Committing adultery or fornication (al-Isra: 30)

11. Committing sodomy

The Prophet (PBUH) said, "Allah will not look at a person (with pleasure) who commits sodomy with a man or a woman" (Sahih al-Jami # 7678)

12. Taking or paying interest (2: 275)

13. Devouring the wealth of orphans (4:10)

14. Forging statements concerning Allah or forging Hadith (al-Zumar: 60)

15. Fleeing from the battle (al-Anfal: 16)

16. Wrongdoing, deception or oppression on the part of the ruler (al-Shura: 42)

17. Being arrogant, boastful, vain (al-Nahl: 23)

18. Giving false testimony (al-Furqan: 72)

19. Drinking alcoholic beverages (5: 90)

20. Gambling (5: 90)

21. Slandering innocent women (al-Nur: 23)

22. Misappropriating something from the booty (3:161)

23. Stealing (5:38)

24. Committing highway robbery (5: 33)

25. Making false oath

Prophet (PBUH) said, "If someone is ordered to take an oath and he takes a false oath in order to take possession of property of a Muslim, then he will incur Allah's wreath when he meets Him" (Sahih al-Jami # 6083)

26. Committing oppression (al-Shuara: 277)

27. Levying illegal taxes

Prophet (PBUH) said, " Do you know who the bankrupt is? The bankrupt form my nation is the one who appears on the Day of Resurrection having performed the prayers, fasted and paid the zakat, but had also abused that person, slandered that person, wrongfully taken the wealth of that person and spilled the blood of that person. These people will take from his good deeds. If his good deeds are thereby exhausted, he will be given their sins and then he will be thrown into the hell-fire" (Sahih al-Jami #87)

28. Consuming forbidden wealth or taking it by any means (2: 188)

29. Committing suicide (4: 29)

30. Being a perpetual liar (3: 61)

31. Ruling by laws other than the laws of Islam (5: 44)

32. Engaging in bribery (2: 188)

33. Women appearing like men and vice-versa

Prophet (PBUH) said, "Allah's curse is upon women who appear like men and upon men who appear like women" (Sahih al-Jami # 4976)

34. Being a dayyouth

Dayyouth: is the one who approves the indecency of his womenfolk and who is void of jealousy or the pimp who facilitates indecency between two people.

Prophet (PBUH) said, "Allah has forbidden the Paradise to three people: the alcoholic, the runaway slave, and the one who is complacent in the face of the evil deeds that his family is performing" (Sahih al-Jami # 3047)

35. Marrying for the purpose of making a woman allowable for another (Baqarah)

36. Not keeping clean from the remains of urine

Ibn Abbas reported that Prophet (PBUH) passed by a grave and said, "These two are being punished and they are not being punished for something hard. But it is a great sin. One of them did not keep himself clean form his urine and the other went around spreading tales" (Sahih al-Jami # 2436)

37. Acting for show (al-Maoon: 4-6)

38. Acquiring knowledge only for worldly gain or concealing knowledge (2: 160)

39. Breaching trusts (al-Anfal: 27)

40. Reminding people of one's kindness (2: 27)

41. Denying predestination (al-Qamar: 49)

"If Allah were to punish the inhabitants of the heavens and earths, then He would punish and He would not be doing injustice to them. If He were to have mercy on them, His mercy would be greater than from their actions. If a person had amount of gold equivalent to Mount Uhud or similar to Mount Uhud and spent it in the Path of Allah, (that spending) would not be accepted form him by Allah until he believes in the preordainment of good and evil. And until he knows that what afflicted him was not going to miss him and what missed him was not going to afflict him. If you were to die with any belief other than that, you would enter the Hellfire" (Kitab al-Sunnah by Ibn Abu Asi # 245. Albani says that its chain is sahih)

42. Eavesdropping on other's private conversation (Hujarat: 12)

43. Spreading harmful tales(al-Qamar: 10)

44. Cursing others

Prophet (PBUH) said, "Abusing a Muslim is evil and fighting him is disbelief" (Sahih al-Jami # 3598)

45. Not fulfilling one's promises

Prophet (PBUH) said, "Whoever has a four characteristic is a complete hypocrite. Whoever posses any of these characteristics has the characteristics of hypocrisy until he gives it up; whenever he makes a promise, he breaks it up…" (Bukhari)

46. Believing in what soothsayers & astrologers say

Prophet (PBUH) said, "Whoever goes to fortuneteller and asks him about something will not have his prayer accepted for forty nights" (Sahih al-Jami # 5816)

47. A wife being rebellious to her husband (4: 34)

48. Putting pictures of beings with souls on clothing, curtains, rocks and any other items

Prophet (PBUH) said, "…the people who will receive the greatest punishment on the day of judgment are those who compete with Allah in creation [those who make pictures or statues]" (sahih al-Jami # 1691)

49. Striking one's self, wailing, tearing one's clothing, pulling one's hair & similar deeds as a form of mourning

Prophet (PBUH) said, "One who strikes his cheeks or tears his clothing and shouts in the manner of pre-Islamic culture is not one of us" (Sahih al-Jami # 5713)

50. Committing injustice (al-Shura: 42)

51. Being overbearing or taking advantage of the weak, slaves, wives or animals

Prophet (PBUH) said, "Allah will torture those who torture people in this world" (Muslim)

52. Harming neighbors

Prophet (PBUH) said, "A person whose neighbor is not safe from his mischief will not enter paradise" (sahih al-Jami # 7002)

53. Harming and abusing Muslims (al-Ahzab: 58)

54. Wearing one's clothes too long, i.e. below the ankles

Prophet (PBUH) said, "What is below the ankles will be in the hellfire " (Bukhari)

55. Harming the slaves of Allah

Prophet (PBUH) said that Allah said, "Whoever shows enmity to a slave of Mine (Allah's) I shall be at war with him" (Sahih al-Jami # 1778)

56. Men wearing silk & gold

Prophet (PBUH) said, "Gold and silk have been permitted for the females of my nation and forbidden for its males" (Sahih al-Jami # 209)

Prophet (PBUH) said, "Men who wears silk in this world will have no portion [of heavens] in the hereafter" (Muslim)

57. Running away of a slave

Prophet (PBUH) said, "If a slave runs away, his prayers will not be accepted" (Sahih al-Jami # 257)

58. Sacrificing animals for other than Allah

Prophet (PBUH) said, "The one who sacrifices for other than Allah is cursed by Allah" (Sahih al-Jami # 4988)

59. Claiming that somebody is one's father while the claimant knows it is not true

Prophet (PBUH) said, "One who claims that someone is his father and knows that it is not true will be forbidden of paradise" (Sahih al-Jami # 5865)

60. Arguing or quarreling for show & not seeking the truth

Prophet (PBUH) said, "Whoever argues in support of something that is wrong and he knows it Allah will be angry with him until he stops" (Sahih al-Jami # 6073)

61. Not allowing excess water to flow to others

Prophet (PBUH) said, "Whoever doesn't allow the access water or pasture for others will not share in the blessings of Allah on the day of judgment" (Sahih al-Jami # 6436)

62. Not measuring the weights properly (al-Mutafafifeen: 1-3)

63. Thinking that one is safe from Allah's planning (al-Araf: 99)

64. Eating carrion, blood or pork meat (al-Anam: 145)

65. Not praying in the congregation & praying by one's self without a valid excuse

Prophet (PBUH) said, "Whoever hears the call to prayer and doesn't come to prayer, there is no prayer for him say for the one who has valid excuse" (Sahih al-Jami # 6176)

66. Continually not performing the Friday prayers and congregational prayers without any valid excuse

Prophet (PBUH) said, "If people don't stop abandoning the Friday Prayers Allah may seal their hearts and they will become headless" (Muslim)

67. Harming others by manipulation one's bequests (4: 12)

68. Being deceitful or deceptive (Fatir: 43)

69. Spying on the Muslims & pointing out their secrets (al-Kalam: 11)

70. Abusing or reviling anyone of the Companions of the Prophet (PBUH)

Prophet (PBUH) said, "Do not revile my companions for, by the one in whose hands is my soul, if you were to spend in charity a mountain of gold similar to mount Uhud it would not be equal to a handful or a half a handful (or what they have done)" (Sahih al-Jami # 7187)

Please make sincere repentance to Allah before as Ali (ra) said, "Today is deed without reckoning and tomorrow is reckoning without deeds". Sincere repentance has four conditions:

• Feeling bad for the sin.
• Firm commitment in intention not to repeat sin (whether it happens again is not a condition if one tried his best).
• Make repentance to Allah by Du'a and asking or better crying for forgiveness.
• If some person has been wronged because of this sin then one needs to make up to this person.