“Every believer, even if he is a disobedient sinner [faasiq]– then it is forbidden to boycott him if there is no benefit in that boycotting.
If there is benefit in the boycotting then we do it because at that point the boycotting would be a cure.
But when there is no benefit in it or when it results in an increase in disobedience and insolence–then leaving that which has no benefit is the benefit.”
Fataawaa fil-Aqidah, vol. 2, p. 1098.
(Shaikh Ibn Uthaimeen, may Allaah have mercy on him)
Questioner: Your eminence, Shaikh, in this residence there are some youth, may Allaah guide them, who will pass by a person and not give him salaam because he follows a Shaikh he hates or follows a Jamaa’ah which differs from his manhaj, so what do you advise them, may Allaah reward you with good?
Shaykh Uthaymeen: This question has been addressed before and the answer is that this is not from the way of the believers and nor from the way of the Salaf as-Saalih and that it is not permissible for a person to boycott his brother for more than three days, such that they meet and this one turns away and that one turns away. The better of the two is the one who initiates the salaam.
Thus it is obligatory on you, firstly, not to attach loyalty and disownment/love and hate [al-Walaa wal-Baraa] to people, because loyalty and disownment is connected to meanings.
As for someone who attaches it to people then he resembles the state of children playing in the street [when they say], “You’re either with me or him …” and this is wrong.
So it is obligatory on you to pay heed to your lessons and to not become busy with, “It was said … he said ..” and we ask Allaah سبحانه وتعالى to give our brothers who have made the mistakes they have, guidance and success in following the Truth, because a person is only human and needs help.
Wasaya wa Towjihat li-Tullaabil-Ilm, pp. 453-454.