Following Bona fide devotee of the Lord

The only condition for successfully executing such spiritual activities is that they must be conducted under the guidance of a pure devotee who is completely free from all mundane desires, fruitive activities and dry speculations about the nature of the Lord. No one has to discover the nature of the Lord. 

It is already spoken by the Lord Himself in the Bhagavad-gita especially and in all other Vedic literatures generally. We have simply to accept them in toto and abide by the orders of the Lord. That will guide us to the path of perfection. One can remain in his own position. No one has to change his position, especially in this age of variegated difficulties. 

The only condition is that one must give up the habit of dry speculation to become one with the Lord. And after giving up such lofty puffed up vanities, one may very submissively receive the orders of the Lord in the Bhagavad-gita or Bhagavatam from the lips of a bona fide devotee. That will make everything successful, without a doubt. SB 1. 5.36