It was narrated from abu Hurairah that the Prophet - and Ahmad said in his Hadith:"The Messenger of Allah said: 'No one who commits Zina is a believer at the moment when he is committing Zina; no one who steals is a believer at the moment when he is stealing; no one who drinks wine is a believer at the moment when he is drinking it; but repentance is available to him after that

English translation · Sunan an-Nasa'i