Transcendental service to the Lord is not mundane. The service attitude of the devotee gradually increases and never becomes slackened. Generally, in old age a person is allowed retirement from mundane service. But in the transcendental service of the Lord there is no retirement at all; on the contrary, the service attitude increases more and more with the progress of age. In the transcendental service there is no satiation, and therefore there is no retirement. Materially, when a man becomes tired by rendering service in his physical body, he is allowed retirement, but in the transcendental service there is no feeling of fatigue because it is spiritual service and is not on the bodily plane. Service on the bodily plane dwindles as the body grows older, but the spirit is never old, and therefore on the spiritual plane the service is never tiresome.
(Srimad Bhagavatam----3:2:3----purport).

The difference between the impersonalistic mental speculators and the pure devotees of the Lord is that the former pass through a miserable understanding of the Absolute Truth at every stage, whereas the devotees enter into the kingdom of all pleasures even from the beginning of their attempt. The devotee has only to hear about devotional activities, which are as simple as anything in ordinary life, and he also acts very simply, whereas the mental speculator has to pass through a jugglery of words, which are partially facts and partially a make-show for the maintenance of an artificial impersonal status. In spite of his strenuous efforts to attain perfect knowledge, the impersonalist attains merging into the impersonal oneness of the brahmajyoti of the Lord, which is also attained by the enemies of the Lord simply because of their being killed by Him. The devotees, however, attain to the highest stage of knowledge and renunciation and achieve the Vaikuṇṭhalokas, the planets in the spiritual sky. The impersonalist attains only the sky, and does not achieve any tangible transcendental bliss, whereas the devotee attains to the planets where real spiritual life prevails. With a serious attitude, the devotee throws away all achievements like so much dust, and he accepts only devotional service, the transcendental culmination.
(Srimad Bhagavatam----3:5:46----purport).

The difference between the impersonalists and the personalists is that the impersonalists, limited by their speculative processes, cannot even approach the Supreme Personality of Godhead, whereas the devotees please the Supreme Personality of Godhead through His transcendental loving service. Sevonmukhe hi: due to the service attitude of the devotee, the Lord is revealed to him. The Supreme Lord cannot be understood by materialistic persons even though He is present before them. In Bhagavad-gītā, Lord Kṛṣṇa therefore condemns such materialists as mūḍhas. Mūḍha means "rascal." It is said in the Gītā, "Only rascals think of Lord Kṛṣṇa as an ordinary person. They do not know what Lord Kṛṣṇa's position is or what His transcendental potencies are." Unaware of His transcendental potencies, the impersonalists deride the person of Lord Kṛṣṇa, whereas the devotees, by dint of their service attitude, can understand Him as the Personality of Godhead.
(Srimad Bhagavatam----4:7:31----purport).

Just like a desire tree, a Vaiṣṇava can fulfill all the desires of anyone who takes shelter of his lotus feet. Prahlāda Mahārāja is a typical Vaiṣṇava. He prays not for himself, but for all living entities—the gentle, the envious and the mischievous. He always thought of the welfare of mischievous persons like his father, Hiraṇyakaśipu. Prahlāda Mahārāja did not ask for anything for himself; rather, he prayed for the Lord to excuse his demoniac father. This is the attitude of a Vaiṣṇava, who always thinks of the welfare of the entire universe.
(Srimad Bhagavatam----5:18:9----purport).

When Vāmanadeva appeared before Bali Mahārāja, Bali Mahārāja immediately wanted to offer Him respectful obeisances, but he was unable to do so because of the presence of Śukrācārya and other demoniac associates. The Lord is so merciful, however, that although Bali Mahārāja did not actually offer obeisances but only endeavored to do so within his mind, the Supreme Personality of Godhead blessed him with more mercy than even the demigods could ever expect. As confirmed in Bhagavad-gītā (2.40), svalpam apy asya dharmasya trāyate mahato bhayāt: "Even a little advancement on this path can protect one from the most dangerous type of fear." The Supreme Personality of Godhead is known as bhāva-grāhī janārdana because He takes only the essence of a devotee's attitude. If a devotee sincerely surrenders, the Lord, as the Supersoul in everyone's heart, immediately understands this. Thus even though, externally, a devotee may not render full service, if he is internally sincere and serious the Lord welcomes his service nonetheless. Thus the Lord is known as bhāva-grāhī janārdana because He takes the essence of one's devotional mentality.
(Srimad Bhagavatam----8:23:2----purport).

This should be the attitude of all devotees. When the Supreme Personality of Godhead recognizes a devotee, He gives him intelligence and dictates how he may go back home, back to Godhead. This is confirmed in Śrīmad Bhagavad-gītā (10.10):
teṣāṁ satata-yuktānāṁ bhajatāṁ prīti-pūrvakam
dadāmi buddhi-yogaṁ taṁ yena mām upayānti te
"To those who are constantly devoted to serving Me with love, I give the understanding by which they can come to Me." The opportunity to engage in the transcendental loving service of the Lord is open to everyone because every living entity is constitutionally a servant of the Lord. To engage in the service of the Lord is the natural function of the living entity, but because he is covered by the influence of mayā, the material energy, he thinks it to be a very difficult task. But if he places himself under the guidance of a spiritual master and does everything sincerely, immediately the Lord, who is situated within everyone's heart, dictates how to serve Him (dadāmi buddhi-yogaṁ tam). The Lord gives this direction, and thus the devotee's life becomes perfect. Whatever a pure devotee does is done by the dictation of the Supreme Lord. Thus it is confirmed by the author of Śrī Caitanya-caritāmṛta that whatever he wrote was written under the direction of the Śrī Madana-mohana Deity.
(Sri Caitanya Caritamrta----1:8:78----purport).

Many fools, not knowing the transcendental nature of the Hare Kṛṣṇa mahā-mantra, sometimes impede our loudly chanting this mantra, yet one who is actually advanced in the fulfillment of chanting the Hare Kṛṣṇa mahā-mantra induces others to chant also. Kṛṣṇadāsa Kavirāja Gosvāmī explains, kṛṣṇa-śakti vinā nahe tāra pravartana: unless one receives special power of attorney from the Supreme Personality of Godhead, he cannot preach the glories of the Hare Kṛṣṇa mahā-mantra. As devotees propagate the Hare Kṛṣṇa mahā-mantra, the general population of the entire world gets the opportunity to understand the glories of the holy name. While chanting and dancing or hearing the holy name of the Lord, one automatically remembers the Supreme Personality of Godhead, and because there is no difference between the holy name and Kṛṣṇa, the chanter is immediately linked with Kṛṣṇa. Thus connected, a devotee develops his original attitude of service to the Lord. In this attitude of constantly serving Kṛṣṇa, which is called bhāva, he always thinks of Kṛṣṇa in many different ways. One who has attained this bhāva stage is no longer under the clutches of the illusory energy. When other spiritual ingredients, such as trembling, perspiration and tears, are added to this bhāva stage, the devotee gradually attains love of Kṛṣṇa.
(Sri Caitanya Caritamrta----1:7:83----purport).

For a pure devotee, it is the same whether he materially constructs a path or constructs one within his mind. This is because the Supreme Personality of Godhead, Janārdana, is bhāva-grāhī, or appreciative of the sentiment. For Him a path made with actual jewels and a path made of mental jewels are the same. Though subtle, mind is also matter, so any path—indeed, anything for the service of the Lord, whether in gross matter or in subtle matter—is accepted equally by the Supreme Personality of Godhead. The Lord accepts the attitude of His devotee and sees how much he is prepared to serve Him. The devotee is at liberty to serve the Lord either in gross matter or in subtle matter. The important point is that the service be in relation with the Supreme Personality of Godhead.
(Sri Caitanya Caritamrta----2:1:161----purport).

Anyone, whether an ordinary materialistic person or a pure devotee, can understand the behavior of Śrī Caitanya Mahāprabhu's devotees if he studies it minutely. One will thus find that the devotees of Śrī Caitanya Mahāprabhu are not at all attached to any kind of material enjoyment. They have completely given up sense enjoyment to engage fully in the service of Lord Śrī Kṛṣṇa and dedicate their lives and souls to serving Kṛṣṇa without material desires. Because their devotional service is free from material desires, it is unimpeded by material circumstances. Although ordinary men have great difficulty understanding this attitude of the devotees, it is greatly appreciated by the Supreme Personality of Godhead, Lord Śrī Caitanya Mahāprabhu.
(Sri Caitanya Caritamrta----3:6:220----purport).

Kṛṣṇa becomes obliged to the loving spirit of the devotee and not exactly to the service rendered. No one can serve Kṛṣṇa completely. He is so complete and self-sufficient that He has no need of any service from the devotee. It is the devotee's attitude of love and affection for Kṛṣṇa that makes Him obliged. A very nice example of this obligatory behavior was manifested when Sudāmā Vipra went to Kṛṣṇa's palace. Sudāmā Vipra had been a class friend of Kṛṣṇa's, and due to his poverty he was induced by his wife to see Kṛṣṇa to request some aid. When Sudāmā Vipra reached Kṛṣṇa's palace, Kṛṣṇa received him very well, and both He and His wife washed the feet of Sudāmā Vipra, showing respect to the brāhmaṇa. Remembering His loving affairs with Sudāmā in their childhood, Kṛṣṇa began to shed tears while receiving him.
(Krsna Book).

As for the urges of the tongue, we all experience that the tongue wants to eat palatable dishes. Generally we should not allow the tongue to eat according to its choice, but should control the tongue by supplying prasāda. The devotee's attitude is that he will eat only when Kṛṣṇa gives him prasāda. That is the way to control the urge of the tongue. One should take prasāda at scheduled times and should not eat in restaurants or sweetmeat shops simply to satisfy the whims of the tongue or belly. If we stick to the principle of taking only prasāda, the urges of the belly and tongue can be controlled.
(Nectar of Instruction).