Bhagavad Gita Chapter 5, Verse 6

सन्न्यासस्तु महाबाहो दुःखमाप्तुमयोगतः | योगयुक्तो मुनिर्ब्रह्म नचिरेणाधिगच्छति ||

sannyāsas tu mahā-bāho duḥkham āptum ayogataḥ yoga-yukto munir brahma nacireṇādhigacchati

But renunciation, O mighty-armed Arjuna, is difficult to achieve without yoga. The sage who is engaged in yoga quickly attains Brahman.

Krishna explains why karma yoga is superior: renunciation (sannyāsaḥ) is difficult (duḥkham) to achieve without yoga (ayogataḥ). Physical withdrawal without inner discipline is painful and nearly impossible. But the sage (muniḥ) who is engaged in yoga (yoga-yuktaḥ) quickly (na cireṇa) attains Brahman. This means action with detachment is easier and faster than trying to renounce without discipline. The key insight: you can't truly renounce without first developing detachment through action. Yoga (selfless action) prepares you for renunciation. Trying to renounce without yoga is like trying to jump without learning to walk—it's difficult and often fails.