The qualification of a spiritual master is that he must have realized the conclusion of the scriptures by deliberation and arguments and thus be able to convince others of these conclusions. Such great personalities who have taken shelter of the Supreme Godhead, leaving aside all material considerations, are to be understood as bona fide spiritual masters.
In the devotional service of the Lord, the only qualification required is surrender. Surrendering oneself is in one’s hand. If one likes, he can surrender immediately, without delay and that begins his spiritual life.
Srimad Bhagavatam begins with the surrender of the devotee unto the Absolute Person. The devotee is fully aware that he is one with the Absolute and at the same time he is in the eternal position of servant to the Absolute.
The living entity’s position is to be under the protection of the illusory energy or under Krishna’s personal protection. When a living entity is fully surrendered, he is under the direct protection of Krishna and Krishna gives him all intelligence by which he can advance in spiritual realization.