When a devotee is engaged in the service of the Lord, it is called the attainment of yoga. The English equivalent to the word "yoga" is "linking up." So actual linking up with Kṛṣṇa, the Supreme Personality of Godhead, begins when the devotee renders service unto Him. Devotees situated in the transcendental rasa of servitorship render their particular service whenever there is an opportunity. Sometimes they sit down in front of Kṛṣṇa to receive orders. Some persons are reluctant to accept this level of devotional service as actual bhakti-yoga, and in some of the Purāṇas also this servitorship in devotional service to Kṛṣṇa is not accepted as the actual bhakti-yoga system. But in the Śrīmad-Bhāgavatam it has been clearly indicated that the servitor relationship with Kṛṣṇa is the actual beginning of yoga realization.
In the Eleventh Canto of Śrīmad-Bhāgavatam, 3rd Chapter, 33rd verse, it is stated that when devotees are engaged in the discharge of bhakti-yoga, sometimes they cry from thinking of Kṛṣṇa, sometimes they laugh, sometimes they become jubilant, and sometimes they talk in very uncommon ways. Sometimes they dance, sometimes they sing, sometimes they are actually engaged in the service of the Lord, and sometimes they sit down silently as if absorbed in trance.
Similarly, in the Seventh Canto of Śrīmad-Bhāgavatam, Chapter 28, Prahlāda Mahārāj says to his friends: "My dear friends, as soon as pure devotees of Lord Kṛṣṇa hear of the transcendental pastimes of the Lord, who is the eternal reservoir of pastimes, or hear about His transcendental qualities they become overpowered with jubilation. Ecstatic symptoms are manifested in their bodies. They shed tears, talk falteringly, glorify the Lord in a loud voice and chant and dance in ecstasy. These ecstasies are always there, but sometimes they overcome all limits, and the symptoms become manifest to all."
In the process of surrender unto the Supreme Personality of Godhead there are six items: to accept everything which is favorable for devotional service, to reject everything which is unfavorable for devotional service, to believe that Kṛṣṇa will always give protection, to identify oneself with Kṛṣṇa's devotees, to always feel inability without the help of Kṛṣṇa, and to always think oneself inferior to Kṛṣṇa, even though one may have full capacity to perform something on his own. When one is substantially convinced that he is always protected by Kṛṣṇa in all circumstances, that feeling is called reverential devotion. Reverential devotion is executed in relation with the Supreme Personality of Godhead and with His other protected devotees.
When Kṛṣṇa was residing in Dvārakā, some of the elderly members of the Yadu family would occasionally put some important matter before Him. At such a time, Kṛṣṇa would carefully give attention to those matters. And if there were some humorous topics mentioned, Kṛṣṇa would immediately respond with a smiling face. Sometimes when Kṛṣṇa was executing His duties in the assembly known as Sudharmā, He would ask the elderly members for good advice. By such activities He is manifest as the supreme spiritual master, the supreme executive head, the superior intelligence, the supreme power, protector and maintainer.