In this connection Śrīmat Prabodhānanda Sarasvatī has composed the following verses in his Caitanya-candrāmṛta (37, 36, 34):

acaitanyam idaṁ viśvaṁ yadi caitanyam īśvaram
na viduḥ sarva-śāstra-jñā hy api bhrāmyanti te janāḥ

“This material world is without Kṛṣṇa consciousness. Lord Caitanya Mahāprabhu is Kṛṣṇa consciousness personified. Therefore if a very learned scholar or scientist does not understand Śrī Caitanya Mahāprabhu, certainly he is wandering uselessly in this world.”

prasārita-mahā-prema- pīyūṣa-rasa-sāgare
caitanya-candre prakaṭe yo dīno dīna eva saḥ

“A person who does not take advantage of the nectar of devotional service overflowing during the presence of Śrī Caitanya Mahāprabhu’s cult is certainly the poorest of the poor.”

avatīrṇe gaura-candre vistīrṇe prema-sāgare
suprakāśita-ratnaughe yo dīno dīna eva saḥ

“The advent of Lord Caitanya Mahāprabhu is just like an expanding ocean of nectar. One who does not collect the valuable jewels within this ocean is certainly the poorest of the poor.”

Similarly, Śrīmad-Bhāgavatam (2.3.19, 20, 23) states:

śva-viḍ-varāhoṣṭra-kharaiḥ
 saṁstutaḥ puruṣaḥ paśuḥ
na yat-karṇa-pathopeto
 jātu nāma gadāgrajaḥ

bile batorukrama-vikramān ye
 na śṛṇvataḥ karṇa-puṭe narasya
jihvāsatī dārdurikeva sūta
 na copagāyaty urugāya-gāthāḥ

jīvañ chavo bhāgavatāṅghri-reṇuṁ
 na jātu martyo ’bhilabheta yas tu
śrī-viṣṇu-padyā manujas tulasyāḥ
 śvasañ chavo yas tu na veda gandham

“A person who has no connection with Kṛṣṇa consciousness may be a very great personality in so-called human society, but actually he is no better than a great animal. Such big animals are generally praised by other animals like dogs, hogs camels and asses. A person who does not lend his aural reception to hearing about the Supreme Personality of Godhead must be considered to have earholes like holes in a field. Although that person has a tongue, it is like the tongue of a frog, which unnecessarily creates a disturbance by croaking, inviting the snake of death. Similarly, a person who neither takes advantage of the dust of the lotus feet of great devotees nor smells the tulasī leaves offered to the lotus feet of the Lord must be considered dead even though he is supposedly working.”

Similarly, Śrīmad-Bhāgavatam 10.1.4 states:

nivṛtta-tarṣair upagīyamānād
 bhavauṣadhāc chrotra-mano-’bhirāmāt
ka uttamaśloka-guṇānuvādāt
 pumān virajyeta vinā paśu-ghnāt

“Who but the animal-killer or the killer of the soul will not care to hear glorification of the Supreme Personality of Godhead? Such glorification is enjoyed by persons liberated from the contamination of this material world.”

Similarly, Śrīmad-Bhāgavatam 3.23.56 says, na tīrtha-pada-sevāyai jīvann api mṛto hi saḥ: “Although a person is apparently living, if he does not serve the lotus feet of great devotees he is to be considered a dead body.”