Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 32

Sanskrit:

अग्नौ गुरावात्मनि च सर्वभूतेषु मां परम् ।अपृथग्धीरुपासीत ब्रह्मवर्चस्व्यकल्मष: ॥ ३२ ॥

ITRANS:

agnau gurāv ātmani casarva-bhūteṣu māṁ paramapṛthag-dhīr upasītabrahma-varcasvy akalmaṣaḥ

Translation:

Thus enlightened in Vedic knowledge by service to the spiritual master, freed from all sins and duality, one should worship Me as the Supersoul, as I appear within fire, the spiritual master, one’s own self and all living entities.

Purport:

One becomes glorious and enlightened by faithfully serving a bona fide spiritual master, who is expert in the Vedic way of life. Thus purified, one never engages in sinful activities, which immediately extinguish the fire of spiritual enlightenment; nor does one become foolish and small-minded, trying to exploit material nature for personal sense gratification. A purified human being is apṛthag-dhī, or without consciousness of duality, because he has been trained to observe the Supreme Personality of Godhead within all things. Such sublime consciousness should be systematically taught throughout the world so that human society will become peaceful and sublime.