In spiritual life, one must conduct one’s whole life under the guidance of the guru. Only one who executes his spiritual life under the direction of the spiritual master can achieve the mercy of Kṛṣṇa. Yasya prasādād bhagavat-prasādaḥ. If one desires to advance in spiritual life but he acts whimsically, not following the orders of the spiritual master, he has no shelter. Yasyāprasādān na gatiḥ kuto ‘pi.

(SB 7.12.11p)