Ruling on delivering lectures and holding seminars in the premises of groups that deviate from the methodology of the pious predecessors?

Al-Halali: Following this answer, may Allah bless you, our teacher. Some associations and centers belonging to certain groups invite some of our brothers, the students of knowledge, to deliver lectures or hold seminars in these centers. The position of some of our brothers is hesitation, and I am one of them. If we go to them, they spread among the people that we are one of them. If we do not go to them, we may be depriving the people there of good. So what is your advice, may Allah bless you in your life, in obedience to Allah, Blessed and Exalted is He, for us and for our brothers, the students of knowledge?

The Shaykh : I think a question like this has come up before, and it was answered as well. So I say: It is not befitting for any of us to be concerned with the people's stance toward him if he knows from himself that he is upright with his Lord, Mighty and Majestic. What did this Khubayb say, or who was it?
Al-Halabi : Abu

The Shaykh : Abu, "And I do not care when I am killed a Muslim *** On which side my body falls for Allah" It does not concern us what people say, but truly what we should be concerned with is what will be said and what will be, meaning our account with the Lord of people. So the question you directed just now: you were invited, or I was invited, or someone else was invited to deliver a word in a group that does not belong to the call of the pious predecessors. They may have a call more specific than our call, and it may differ from ours in some of what we hold, and it may coincide with ours, and so on. If you are invited, the important thing is that you be frank when you deliver your word to these people. Do not conceal from them and do not equivocate with them, but rather say the word of truth, especially in that society where they may not hear this word of truth from anyone else. If you or someone else follows the path of truth by speaking in the midst of that group or another with the call of truth by which he worships Allah, the others will not be able to say the statement that you fear will be said about you. And we have said that it is not befitting for us to care, but we do not deny that if we can prevent people from attacking us without right, it is our duty to do so. Because, as he (peace and blessings be upon him) said, , in this case, if we repeat delivering the word of truth in such societies, those people will not be able to say that so-and-so has become one of them, unless they intend to say a word of falsehood. And we cannot prevent them from saying it. And they said about the prophets and messengers what they said, so it is even more likely and more fitting that they say about us what they said about the prophets and messengers, or more than that. So my conclusion to the answer is: engaging with these groups is conditional on your word supporting your call, and you not concealing from them or equivocating with them.
Al-Halali: May Allah reward you with good.

The Shaykh : And you. Now, our other brothers, they have nothing because it is time to depart.