Bhagavad Gita Chapter 03, Text 04

Bg 3.4

na karmanam anarambhan
naiskarmyam puruso ’snute
na ca sannyasanad eva
siddhim samadhigacchati

Word for word: 
na — not; karmanam — of prescribed duties; anarambhat — by nonperformance; naiskarmyam — freedom from reaction; purusah — a man; asnute — achieves; na — nor; ca — also; sannyasanat — by renunciation; eva — simply; siddhim — success; samadhigacchati — attains.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Not by merely abstaining from work can one achieve freedom from reaction, nor by renunciation alone can one attain perfection.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The renounced order of life can be accepted when one has been purified by the discharge of the prescribed form of duties which are laid down just to purify the hearts of materialistic men. Without purification, one cannot attain success by abruptly adopting the fourth order of life (sannyasa). According to the empirical philosophers, simply by adopting sannyasa, or retiring from fruitive activities, one at once becomes as good as Narayana. But Lord Krishnadoes not approve this principle. Without purification of heart, sannyasa is simply a disturbance to the social order. On the other hand, if someone takes to the transcendental service of the Lord, even without discharging his prescribed duties, whatever he may be able to advance in the cause is accepted by the Lord (buddhi-yoga). Sv-alpam apy asya dharmasya trayate mahato bhayat. Even a slight performance of such a principle enables one to overcome great difficulties.