How should one deal with a Muslim friend who has been proven to have committed adultery, consumed alcohol, and gambled? Is it permissible to boycott him or should one maintain his companionship hoping for his repentance, especially since "a man is upon the religion of his intimate friend" and Allah Almighty says: "And let no pity for them overcome you in the religion of Allah, if you should believe in Allah and the Last Day"?

The disobedient one should be advised secretly with wisdom, without public shaming or violence, and with prayers for his guidance. If he does not desist, and shunning him would deter him, then shun him, for sharia permits shunning disobedient individuals for a beneficial purpose. If it is highly probable that shunning him will not reform him, then continuing to advise him is better, while minimizing interaction so that his disobedience does not affect you. It is obligatory to conceal his faults and not expose him, except for a legitimate sharia interest, for whoever conceals a Muslim, Allah will conceal him.