Real bhakti is raganuga-bhakti. This raganuga-bhakti, we have to come after surpassing the vaidhi-bhakti [regulative process]. In the material world, if we do not try to make further and further progress in devotional service, if we are simply sticking to the sastric [scriptural] regulation process and do not try to go beyond that…
The sastric process is kanistha-adhikara, lowest stage of devotional service… This is nice beginning, but one has to go above this. If I become satisfied only with these regulative principles for worshipingi but if I have no other idea, then sa bhaktah prakrtah smrtah. Prakrta means on the material platform.
Any devotee can fall down if he remains prakrta-bhakta. So he has to raise himself above this in the madhyama-adhikara [intermediate stage]. Therefore, if we do not associate with the advanced devotees, uttama-adhikari, if we simply want to remain in the lowest stage of devotional service, then we are not making progress. Then we shall simply enjoy the material field, without entering into the spiritual platform.
Srila Prabhupada, Srimad Bhagavatam 1.2.33 lecture, Vrindavan, 12 November 1972