In a hadeeth Rasūl Allāh صلى الله عليه وسلم said:

الوحدة خير من جليس السوء والجليس الصالح خير من الوحدة

"Solitude is better than bad company and good company is better than solitude." [Bayhaqi - Shu'ab al Imaan]

If a person cannot adopt good company, then he should remain in solitude. Nothing is more helpful in achieving sincerity of intention than solitude. When a person is away from the view and attention of people, then it is more likely that his deeds will be sincere. Furthermore, a person often changes his behaviour when associating with different people, thus becoming somewhat hypocritical in his behaviour. One of the unique characteristics of the siddiqeen (truthful ones) is that they prefer to keep away from people other than what is necessary. Solitude also reveals a person's faults to himself. The fewer people a person sees and meets the better it is for the heart.

[This short excerpt is based on a brothers' majlis (gathering held for spiritual training) held by Shaykh Abu Yusuf Riyadh ul Haq on 24th October 2001]