Sharpen the weapon of jnana by service

If one seriously desires to return home, back to Godhead, one must therefore become strong enough by pleasing the spiritual master, for thus one gets the weapon with which to conquer the enemy, and one also gets the grace of Krishna. Simply getting the weapon of jnana is insufficient. One must sharpen the weapon by serving the spiritual master and adhering to his instructions. Then the candidate will get the mercy of the Supreme Personality of Godhead. In general warfare one must take help from his chariot and horses in order to conquer his enemy, and after conquering his enemies he may give up the chariot and its paraphernalia. Similarly, as long as one has a human body, one should fully use it to obtain the highest perfection of life, namely going back home, back to Godhead.

Srimad Bhagavatam 7.15.45 purport