From Abu Sa’eed al-Khudree (radiyallaahu ‘anhu) who said that Allaah’s Messenger said:
The example of the believer with regards to eemaan is like the example of a horse with regards to its tethering stake; it roams around and then returns to its tethering stake, and the believer is negligent and then he turns to his eemaan. So feed the pious with your food and treat the believers well.
[Reported by Ahmad]
So he does not persist upon sin, or treat it lightly. Rather like the rest of the children of Aadam he commits many sins. However he is frequent in turning back in repentance to his Lord.
From: Forty Hadeeth On: The Islamic Personality by ‘Alî Hasan ‘Alî ‘Abdul Hamîd