Cooperation with Opposing Groups in Da'wah

Question:
There is a saying that some callers to Islam have put forward: “We cooperate in what we agree upon, and we excuse one another in what we differ upon.” This is regarding customs; money is exposed to the Muslim from all angles, and some angles are accepted. In the question, some people see no objection to cooperating with certain specific groups and the Rafidah in some matters to support Islam, while others see that there should be no cooperation with them and that distinction is necessary. What is your opinion on this question?

Answer:
Cooperation with associations that may have errors in some of the detailed rulings where independent legal reasoning (ijtihad) is involved, there is nothing wrong with that. As for cooperating with the Rafidah or with deviant Sufis, no, cooperation is not appropriate; rather, they need to be called to Allah. As for mixing with them and cooperating with them, that means it is as if one is satisfied with the evil and religious innovation (bid'ah) they are upon. These people must be boycotted. Whoever wants to commit a bid'ah must be boycotted, or whoever wants to commit an evil must be boycotted if he does not respond. This is how the Salaf and the righteous (may Allah have mercy on them) proceeded in this matter; because if you assume the person who commits a bid'ah or the person who commits an apparent evil, the attendees or those who hear the news will think that you are satisfied with his bid'ah and satisfied with his evil and are lenient in that.