Who requires a guru? It is not a fashion, that one has to accept anyone as guru. No. A person requires a guru when he is inquisitive, tasmād guruṁ prapadyeta jijñāsuḥ, when he is very much eager to understand the spiritual, śreya uttamam. Uttamam. Ut means transcendental, and tama means darkness. This world is called darkness, ignorance. So one who wants to transcend this position of ignorance and wants to know the transcendental subject, means spiritual subject, brahma-jijñāsā, he requires a guru, not any person, other person.
-Lecture Chaitanya Charitamrit Madhya Chapter 20 Verse 101-104 - Bombay

अहं सर्वस्य प्रभवो मत्त: सर्वं प्रवर्तते ।
इति मत्वा भजन्ते मां बुधा भावसमन्विता: ॥ ८ ॥
I am the source of all spiritual and material worlds. Everything emanates from Me. The wise who perfectly know this engage in My devotional service and worship Me with all their hearts.
-Bhagavad-Gita Chapter 10 Verse 8