The Ruling on Cooperating with the Sects in What They Agree Upon

Question:
What is your view on what is currently being circulated by some sects, namely that we should cooperate in what we agree upon and excuse one another in what we differ upon?

Answer:
If the difference is in legal matters, jurisprudential issues, or matters of independent legal reasoning, there is nothing wrong with it. However, if the difference is in matters of creed, no, it is not permissible for us to cooperate in what we agree upon and excuse one another in what we differ upon regarding matters of creed. This is not permissible. This is a vague statement. If it is intended to refer to a difference for which the one who holds it is excused, such as differences in jurisprudential issues and independent legal reasoning, then there is no harm in that.
The Companions used to differ in jurisprudential issues, yet they did not split apart; they were brothers and on good terms. Likewise, the jurists after them differed in jurisprudential issues, but they did not become enemies or cut off ties with one another. Rather, they loved one another and prayed behind one another. As you know, the four schools of jurisprudence are not owned by their followers; the people of the four major schools are brothers, and there is love among them. However, if the difference is in creed, no, not out of love or favor. We do not gather with one who opposes the creed, an innovator, or a disbeliever, until he repents to Allah the Mighty and Majestic and abandons his opposition. Yes.