The Book of Faith (Kitab Al-Iman)
Muslim :: Book 1 : Hadith 171
I heard Abu Dharr narrating it from the Apostle (may peace be upon him) that he observed: Gabriel came to me and gave me the tidings: Verily he who died amongst your Ummah without associating anything with Allah would enter Paradise. I (the narrator) said: Even if he committed adultery and theft. He (the Holy Prophet) said: (Yes), even if he committed adultery and theft.