śruti-smṛti-purāṇādi- pañcarātra-vidhiṁ vinā aikāntikī harer bhaktir utpātāyaiva kalpate

"Devotional service performed without reference to the Vedas, Puranas, Pancaratras, etc., must be considered sentimentalism, and it causes nothing but disturbance to society." There are different grades of Vaisnavas (kanistha-adhikari, madhyama-adhikari, uttama-adhikari), but to be a madhyama-adhikari preacher one must be a learned scholar in Vedanta-sutra and other Vedic literature because when bhakti-yoga develops on the basis of Vedanta philosophy it is factual and steady. In this connection we may quote the translation and purport of the verse mentioned above (Srimad-Bhagavatam, 1.2.12):