Is it obligatory to point out the errors of the Tabligh group and warn people against them?

The questioner:
We are taking a call from Bandar from Riyadh. Bandar, please go ahead. Peace be upon you. And upon you be peace. May Allah keep you in good health, O Shaykh. And upon you be peace. Even more so. Thank you. Bandar, turn off the television, may Allah grant you well-being. O Shaykh, I was with the Tabligh group. It became clear to me that their methodology is primitive and involves Sufism, and I left them after about five years. So now, am I able to warn people against them, O Shaykh? Is it permissible for me to warn against them, especially since our brothers in Saudi Arabia take them as a means of da'wah (calling to Islam) and such? Good, the question is clear to you.

The Shaykh:
My brother, in Saudi Arabia, and praise be to Allah, we have da'wah. We have an independent Ministry of Islamic Affairs and Guidance, and it has scholars. We are on the right path and on the creed of tawhid (the oneness of Allah), and we do not need to use unknown da'wah groups whose origins we do not know.
And since you have come to know this, and praise be to Allah, and it has become clear to you what the Tabligh group holds, it is obligatory for you to warn against them; you have no room for silence. You must point out their faults; it is obligatory for you to warn against them. This is part of giving sincere advice. The Prophet (peace and blessings be upon him) said: We are, praise be to Allah, in the land of tawhid, in the land of da'wah. We have a ministry dedicated to da'wah and guidance. How do they come and call to Allah, and they invade our lands, they invade our sons, they invade the villages and the desert? It is not permissible to allow them to do this. It is obligatory that the da'wah workers appointed by the state, who have the qualification, should spread in these lands, and that there be no room for others who bring us harm. Yes.

The presenter:
May Allah reward you with good, O Shaykh Salih. In fact, if you allow me to ask a question specific to this topic, it is that the youth need to be with their trusted, divinely guided scholars, asking them and turning to them. Perhaps you also have guidance on this point, O Shaykh?

The Shaykh:
Yes, the Prophet (peace and blessings be upon him) said: "Hold fast to the community, for " And he said to Hudhayfah ibn al-Yaman: "Stick to the community of the Muslims and their imam." So sticking to the community is obligatory, and the one who strays has strayed into the Fire. It is obligatory for us to be with the community of the Muslims, with our rulers, and with our scholars, and with the correct creed we were raised upon and learned in our schools and mosques. We do not import from here and there, or give the opportunity to those who come to us from here and there, whose origins we do not know, where they learned we do not know, and what their method is we do not know. Yes.

The presenter:
May Allah reward you.