Persons who hear Śrīmad-Bhāgavatam regularly and are always taking the matter very seriously will have the Personality of Godhead Śrī Kṛṣṇa manifested in their hearts within a short time.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
शृण्वतः श्रद्धया नित्यं गृणतश्च स्वचेष्टितम् । कालेन नातिदीर्घेण भगवान् विशते हृदि
śṛṇvataḥ śraddhayā nityaṃ gṛṇataśca svaceṣṭitam | kālena nātidīrgheṇa bhagavān viśate hṛdi
SB 2.8.4