Sayyiduna Abu Hurairah (may Allah be pleased with him) said that the Noble Prophet (peace and blessings be upon him) said: When a person commits adultery, at the very moment of committing adultery, he is not a believer; similarly, when someone drinks wine, at the very moment of drinking wine, he is not a believer; likewise, when a thief steals, at that time he is not a believer. And in one narration there is an addition: If a person (in broad daylight) commits robbery on someone's property in such a way that people are watching, he does not commit this looting while remaining a believer.
Hadith Referenceاللؤلؤ والمرجان / كتاب الايمان / 36
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 74 كتاب الأشربة: 1 باب قول الله تعالى: (إنما الخمر والميسر والأنصاب والأزلام رجس من عمل الشيطان»