Philosophical research culminates in understanding the Supreme Personality of Godhead. After achieving this understanding, when one becomes free from the material modes of nature he attains the stage of devotional service. Either by devotional service directly or by philosophical research, one has to find the same destination, which is the Supreme Personality of Godhead.
If one sincerely searches for spiritual salvation, then Krishna, being situated in everyone’s heart, gives him the intelligence to find a suitable spiritual master. By the grace of a spiritual master, one gets the proper instructions and advances in his spiritual life.
Even though one may be very learned and wise, he is mad if he does not understand that the endeavor for sense gratification is a useless waste of time. Being forgetful of his own interest, he tries to be happy in the material world, centering his interests on his home, which is based on sexual intercourse and which brings him all kinds of material miseries. In this way one is no better than a foolish animal.
Although the motive (of a devotee) might be impure, the Lord does not consider the motive; He is concerned with the service. However if a devotee has a particular motive, the Lord directly or indirectly knows it and therefore, He does not leave the devotee’s material desire unfulfilled. These are some of the special favours by the Lord to a devotee.