Sayyiduna Abu Hurairah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "The adulterer does not commit adultery while he is a believer, the thief does not steal while he is a believer, and the one who drinks wine does not drink it while he is a believer."
Hadith Referenceسنن دارمي / من كتاب الاشربة / 2143
Hadith Takhrijاس روایت کی سند صحیح اور حدیث متفق علیہ ہے۔ دیکھئے: [بخاري 2475] ، [مسلم 57] ، [أبوداؤد 4689] ، [نسائي 4886] ، [مسند أبى يعلی 6299] ، [ابن حبان 186] ، [الحميدي 1162]
Brief Explanation
(Commentary on Hadith 2142)
The meaning of this hadith is that at the time of committing the aforementioned sins, a person does not remain a believer; faith leaves his heart. Therefore, if someone who commits adultery, theft, or drinks alcohol claims to be a Muslim, he is lying in his claim. A Muslim who possesses faith cannot commit such acts. Rather, if he ever does commit a major sin (kabirah), he becomes extremely remorseful and then repents forever, remaining engrossed in seeking forgiveness (istighfar) for his sin.