Caitanya Mahaprabhu has plainly warned that “Don’t go to Mayavadis.” Mayavadi-bhasya sunile haya sarva-nasa. Mayavadi haya krsne aparadhi. This is the statement of Sri Caitanya Mahaprabhu.

So you should be very, very careful. Don’t go to hear any Mayavadi. There are many Mayavadis in the dress of Vaisnavas. Sri Bhaktivinoda Thakura has explained about them, that ei ‘ta eka kali-cela nake tilaka gale mala, that “Here is a follower of Kali. Although he has got a tilaka on the nose and neck beads, but he’s a kali-cela.” If he’s Mayavadi, sahaja-bhajana kache mama sange laya pare bala. So these things are there. You have come to Vrndavana. Be careful, very careful. Mayavadi-bhasya sunile [Cc. Madhya 6.169]. There are many Mayavadis here, many so-called tilaka-mala, but you do not know what is there inside.

They create disturbance only. Therefore we have to follow the Gosvamis, Gosvami literature, especially Bhakti-rasamrta-sindhu, which we have translated in The Nectar of Devotion. Every one of you should very carefully read and make progress. Don’t be victimized by the Mayavadi so-called Vaisnava. It is very dangerous.

From Srila Prabhupada’s lecture on Srimad-Bhagavatam 1.7.8 — September 7, 1976, Vrndavana