Which is the greatest of all sins according to the Holy Prophet (SAW)?
Q1. Which is the greatest of all sins according to the Holy Prophet (SAW)?
Answer: Shirk
Explanation: Shirk (associating partners with Allah) is the greatest sin in Islam, as affirmed in the Quran (4:48) where Allah states He will not forgive shirk, and by multiple hadith of the Prophet (PBUH).