You’re chanting and chanting, but are you learning any philosophy? Really learning it so it makes sense? Chanting without knowledge of what the chanting means is not very effective.
bahu janma kare yadi śravaṇa, kīrtana
tabu ta’ nā pāya kṛṣṇa-pade prema-dhana
— Caitanya Caritāmṛta (adi.8.16)
Chanting can go on ineffectively for many, many births (bahu janma). Something is required before it becomes effective. That requirement is Śrī Caitanya’s “mercy” – what is that “mercy” it is the instructions about the meaning of Śrīmad Bhāgavatam left behind by his followers, particularly the Six Goswami’s of Vrindavan. So we have to study their books (particularly bhakti-rasāmṛta-sindhu, ṣaḍ-sandarbha, and bṛhat-bhāgavatāmṛta) until we really understand what they are saying. Then our chanting has effect very quickly, because we chant properly, without mistake, without “offense” without misconception.
Śrīla Prabhupāda therefore instructed us to study these books. We have to study Śrīmad Bhāgavatam through understanding the way Bhāgavatam is explained in these books. Śrīla Prabhupāda’s writings lay the foundation for this study, but one cannot really say he follows Śrīla Prabhupāda’s instructions unless he also takes the trouble to follow his instructions to directly study the works of the Six Goswāmīs.