Is it permissible to sit with the people of innovation in order to call them to the truth?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: Some people sit with the people of innovation, parties, and opposing groups, and they continue with them for many long years. When they are told, "Do not sit with them," they say, "This is in the category of da'wah (calling others to Islam) so that I may return them to the truth." What is the ruling on this action?

Answer:
First, the ruling that they are innovators requires scholars, because some of the brothers declare people to be innovators without having knowledge. He says to everyone who disagrees with him, "You are an innovator." So if it is established that they are innovators, and if you have knowledge—you have knowledge—and if sitting with them is to praise them in order to call them to Allah, there are two conditions: first, that you have knowledge, and second, that you see that you have an influence on them. Then you sit with them; this is calling to Allah. But, my brother, if you do not have knowledge, or if you have knowledge but it does not benefit them in any way and they are stubborn, do not sit with them, because they do not want the truth. Yes.