It was narrated that Abu Hurairah said:
The Messenger of Allah [SAW] said: 'The adulterer is not a believer at the moment when he is committing adultery, and the wine drinker is not a believer at the moment when he is drinking wine, and the thief is not a believer at the moment when he is stealing, and the robber is not a believer at the moment when he is robbing and people are looking on.'