Shaykh Zayd Al-Madkhalee said, “What is apparent to me in this issue [visiting a sick innovator who announces his innovation, calls to it and warns against Salafiyyah and Salafi scholars] is the permissibility of visiting him for whoever has knowledge of the Shariah (Islamic law).
Thus, his first priority for visiting him should be to extend advice to this sick [individual] using a good approach so that he desists from his innovation which he was known for before death meets him and he is in the act of it and a legator of it, clarifying that to him using both transmitted (i.e. the Quran,
the Sunnah, consensus (ijmah) etc.) and intellectual evidences.
Therefore if he responds to it, that is what is required; but if he rejects and persists upon his evil and harmful innovation, he should announce his disavowal from him, declare that he is going to boycott him and warn the people from his innovation – whether he is dead or alive – as a form of advice to the Muslims, a form of reviving the Sunnah, glorifying it, abolishing innovations and establishing the evidences with clarity and precision.
Perhaps [some Salafis]…may find it difficult [to understand] this response if he compared it to the stance of some of the Salaf regarding the people of innovation (who are both) dead and alive. As a result I say to him, indeed, the caller to Allah (i.e. the daa’ee) must possess wisdom so he looks to the advantages/benefits, ills/evil and the circumstances and consequently, he does what is beneficial to the best of his ability.
This answer was elicited from the action of the Prophet (sallalahu alaihi wasallam); he visited a Jew and presented Islam to him. He then became Muslim and so the Prophet (sallalahu alaihi wasallam) praised Allah who saved the Jew from the Fire by him entering into Islam by His Grace, then by the dawah of the Prophet and his advice to him.”
Posted by Abdul Kareem Ibn Ozzie