One must be prepared to offer the necessary respect and honor to the spiritual master. He should not be unnecessarily envious of his Godbrothers. Rather, if a Godbrother is more enlightened and advanced in Kṛṣṇa consciousness, one should accept him as almost equal to the spiritual master, and one should be happy to see such Godbrothers advance in Kṛṣṇa consciousness. A devotee should always be very kind to the general public in instructing Kṛṣṇa consciousness because that is the only solution for getting out of the clutches of māyā. That is really humanitarian work, for it is the way to show mercy to other people who need it very badly. The word śuśrūṣābhiratāya indicates a person who faithfully engages in serving the spiritual master. One should give personal service and all kinds of comforts to the spiritual master. A devotee who does so is also a bona fide candidate for taking this instruction. The word bahir jāta-virāgāya means a person who has developed detachment from external and internal material propensities. Not only is he detached from activities which are not connected to Kṛṣṇa consciousness, but he should be internally averse to the material way of life. Such a person must be nonenvious and should think of the welfare of all living entities, not only of the human beings, but living entities other than human beings. The word śucaye means one who is cleansed both externally and internally. To become actually cleansed externally and internally, one should chant the holy name of the Lord, Hare Kṛṣṇa, or Viṣṇu, constantly.
(Srimad Bhagavatam-----3:32:42----purport).

According to expert opinion, Balarāma, as the chief of the original quadruple forms, is also the original Saṅkarṣaṇa. Balarāma, the first expansion of Kṛṣṇa, expands Himself in five forms: (1) Mahā-saṅkarṣaṇa, (2) Kāraṇābdhiśāyī, (3) Garbhodakaśāyī, (4) Kṣīrodakaśāyī, and (5) Śeṣa. These five plenary portions are responsible for both the spiritual and material cosmic manifestations. In these five forms Lord Balarāma assists Lord Kṛṣṇa in His activities. The first four of these forms are responsible for the cosmic manifestations, whereas Śeṣa is responsible for personal service to the Lord. Śeṣa is called Ananta, or unlimited, because He assists the Personality of Godhead in His unlimited expansions by performing an unlimited variety of services. Śrī Balarāma is the servitor Godhead who serves Lord Kṛṣṇa in all affairs of existence and knowledge. Lord Nityānanda Prabhu, who is the same servitor Godhead, Balarāma, performs the same service to Lord Gaurāṅga by constant association.
(Sri Caitanya Caritamrta----1:5:10----purport).

The śaktyāveśa-avatāras are categorized into (1) forms of divine absorption (bhagavad-āveśa), such as Kapiladeva or Ṛṣabhadeva, and (2) divinely empowered forms (śaktyāveśa), of whom seven are foremost: (1) Śeṣa Nāga in the Vaikuṇṭha world, empowered for the personal service of the Supreme Lord (sva-sevana-śakti), (2) Anantadeva, empowered to bear all the planets within the universe (bhū-dhāraṇa-śakti), (3) Lord Brahmā, empowered with the energy to create the cosmic manifestation (sṛṣṭi-śakti), (4) Catuḥsana, or the Kumāras, specifically empowered to distribute transcendental knowledge (jñāna-śakti), (5) Nārada Muni, empowered to distribute devotional service (bhakti-śakti), (6) Mahārāja Pṛthu, specifically empowered to rule and maintain the living entities (pālana-śakti) and (7) Paraśurāma, specifically empowered to cut down rogues and demons (duṣṭa-damana-śakti).
(Sri Caitanya Caritamrta----2:20:246----purport).

The Lord has many potencies, and He is nondifferent from all these potencies. Because the potencies and the potent cannot be separated, they are identical. Kṛṣṇa is described as the source of all potencies, and He is also identified with the external potency, the material energy. Kṛṣṇa also has internal potencies, or spiritual potencies, which are always engaged in His personal service. His internal potency is different from His external potency. Kṛṣṇa's internal potency and Kṛṣṇa Himself, who is the potent, are always identical.
(Sri Caitanya Caritamrta----2:22:7----purport).

There are concrete examples of how a devotee discharged one of these services and achieved perfection. King Parīkṣit achieved the desired goal of life simply by hearing Śrīmad-Bhāgavatam. Śukadeva Gosvāmī achieved the desired goal of life simply by reciting Śrīmad-Bhāgavatam. Prahlāda Mahārāja became successful in his devotional service by always remembering the Lord. Lakṣmī, the goddess of fortune, was successful by engaging herself in massaging the lotus feet of the Lord. King Pṛthu became successful by worshiping in the temple. Akrūra became successful by offering prayers. Hanumān became successful by rendering personal service to Lord Rāmacandra. Arjuna became successful by being a friend of Kṛṣṇa. And Bali Mahārāja became successful simply by offering all of his possessions to Kṛṣṇa.
(Nectar of Devotion).

The devotees of Kṛṣṇa engaged in His personal service are always very cautious, because they know that becoming personal servitors of Lord Kṛṣṇa is not an ordinary thing. A person who offers respect even to the ants engaged in the service of the Lord becomes eternally happy, so what is there to say of one who offers Kṛṣṇa direct service? Raktaka once said within himself, "Not only is Kṛṣṇa my worshipable and servable Lord, but also the girl friends of Kṛṣṇa, the gopīs, are equally worshipable and servable by me. And not only the gopīs, but anyone who is engaged in the service of the Lord is also worshipable and servable by me. I know that I must be very careful not to become overly proud that I am one of the servitors and devotees of the Lord." From this statement one can understand that the pure devotees, those who are actually engaged in the service of the Lord, are always very cautious and are never overly proud of their service.
(Nectar of Devotion).