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

न कर्मणामनारम्भान्नैष्कर्म्य पुरुषोऽश्न‍ुते ।
न च सन्न्यसनादेव सिद्धिं समधिगच्छति ॥ ४ ॥
Not by merely abstaining from work can one achieve freedom from reaction, nor by renunciation alone can one attain perfection.
- Bhagvad-gita. 3.4