Chapter: The sin of the person who ascribes partners in worship to Allah

When the Verse: 'It is those who believe and confuse not their belief with wrong (i.e., worshipping others besides Allah): (6.82) was revealed, it became very hard on the companions of the Prophet (ﷺ) and they said, "Who among us has not confused his belief with wrong (oppression)?" On that, Allah's Apostle said, "This is not meant (by the Verse). Don't you listen to Luqman's statement: 'Verily! Joining others in worship with Allah is a great wrong indeed.' (31.13)

The Prophet. said, "The biggest of the great sins are: To join others in worship with Allah, to be undutiful to one's parents, and to give a false witness." He repeated it thrice, or said, "....a false statement," and kept on repeating that warning till we wished he would stop saying it. (See Hadith No.7, Vol. 8)

A bedouin came to the Prophet (ﷺ) and said, "O Allah's Messenger (ﷺ)! What are the biggest sins?: The Prophet (ﷺ) said, "To join others in worship with Allah." The bedouin said, "What is next?" The Prophet (ﷺ) said, "To be undutiful to one's parents." The bedouin said "What is next?" The Prophet (ﷺ) said "To take an oath 'Al-Ghamus." The bedouin said, "What is an oath 'Al-Ghamus'?" The Prophet (ﷺ) said, "The false oath through which one deprives a Muslim of his property (unjustly).

A man said, "O Allah's Messenger (ﷺ)! Shall we be punished for what we did in the Prelslamic Period of ignorance?" The Prophet (ﷺ) said, "Whoever does good in Islam will not be punished for what he did in the Pre-lslamic Period of ignorance and whoever does evil in Islam will be punished for his former and later (bad deeds).