If relatives are engaged in wrongdoing, is it obligatory to advise them, and what is the ruling on boycotting them?

Question : The questioner, your sister in Allah (may Allah reward you with good), from Jordan, says in this question: I am, praise be to Allah, committed to the Shari'ah as much as I can and as Allah has enabled me. But I have an uncle who is not upright. This uncle’s family deals in sorcery, lies, and sometimes theft, and they do not pray. The girls wear short clothes and go out with their hair exposed. I and my family say: We have not truly advised them because they do not accept advice, and if we do advise them, they do not respond. I see that staying away from them is better and more beneficial. So, is there sin in our boycotting them, Honorable Shaykh? We ask for your guidance.

Answer : Advising relatives, or as a general rule of advising non-relatives, is based on the saying of Allah, Blessed and Exalted is He, to His Prophet Muhammad (peace and blessings be upon him and his family): And because relatives have rights, if they have rights in giving money and maintaining ties. Indeed, one of the greatest ways of maintaining ties is advising them in the religion of Allah, Mighty and Majestic. Continue advising them in a way that does not bore them, that they do not grow weary of, and that they do not dislike you because of it.
As for boycotting them, one must look at the situation: if boycotting them leads to good, such that they stop the wrongdoing they are engaged in and become upright in what is obligatory upon them, then boycott them. But if there is no good in that, do not boycott them, because maintaining family ties is obligatory, even if they are disobedient, except for one who reaches the state of apostasy, where he never prays. As for these people, boycotting them is obligatory.
Because they are apostates from Islam. Indeed, the one who does not pray is a disbeliever with major disbelief that takes him out of the religion, and he is an apostate from Islam, abiding eternally in the Fire of Hell, refuge sought in Allah. He will be gathered on the Day of Resurrection with Pharaoh, Haman, Qarun, and Abu Jahl. And this means that the one who abandons prayer is a disbeliever with disbelief that takes him out of the religion, an apostate from the religion of Allah, abiding eternally in the Fire of Hell. This is what the Qur'an and the Sunnah indicate, and what has been transmitted from the consensus of the Companions (may Allah be pleased with them). We have a treatise on this, and others have also written treatises on it. And the evidence cited by those who do not consider the one who abandons prayer a disbeliever is not valid evidence, because it is either authentic but not explicit, or weak and unable to withstand the authentic evidence established by the Book of Allah and the Sunnah of His Messenger (peace and blessings be upon him), and what has been transmitted from the consensus of the Companions (may Allah be pleased with them).
If these relatives do not pray, boycotting them is obligatory because they are apostates, and they are not like the original disbeliever about whom Allah the Exalted said: .
For these are original disbelievers, whereas the apostate is not, because he is not confirmed in his religion; rather, he is called to Islam. If he is guided, that is what is desired. If he is not guided, it is obligatory for the authorities to kill him, based on the saying of the Prophet (peace and blessings be upon him): And the disbeliever is one who changes his religion. Thank you, Honorable Shaykh, may Allah reward you, and may Allah bless you and your knowledge, and benefit the Muslims with you.