Such devotees are empowered by the Lord to distribute devotional consciousness, or Kṛṣṇa consciousness, to the people in general. They are known as authorized spiritual masters, and it is by the mercy of such a spiritual master that a conditioned soul gets the seed of devotional service. The causeless mercy of the Supreme Personality of Godhead is first appreciated when one comes in touch with a bona fide spiritual master, who can enlighten the conditioned soul and bring him to the highest position of devotional life. Therefore Lord Caitanya said that by the mercy of the spiritual master one can achieve the causeless mercy of the Lord and by the mercy of the Supreme Personality of Godhead one can attain the mercy of the bona fide spiritual master.
Thus by the mercy of the spiritual master and Kṛṣṇa one receives the seed of devotional service. Then one has to sow the seed in the field of his heart, just as a gardener sows the seed of a valuable tree. After sowing this seed, one has to water it by chanting and hearing the holy name of the Supreme Lord and by taking part in discussions about the science of devotional service in a society of pure devotees. When the plant of devotional service sprouts up from the seed of devotion, it begins to grow freely. When it is fully grown, it surpasses the length and breadth of this universe and enters the transcendental atmosphere of the spiritual world, where everything is bathed in the effulgence of the brahmajyoti. The plant penetrates even the brahmajyoti and gradually enters the planet known as Goloka Vṛndāvana. There the plant takes shelter at the lotus feet of Kṛṣṇa. That is the ultimate goal of devotional service. After attaining this position, the plant produces the fruit of love of Godhead. To taste this fruit, however, it is necessary for the devotee, or transcendental gardener, to water the plant daily by chanting and hearing. Unless one waters the plant by chanting and hearing, there is every chance that it will dry up.