A person in full Kṛṣṇa consciousness acts by the dictation of Kṛṣṇa. In the beginning of Kṛṣṇa consciousness, dictation is received through the transparent medium of the spiritual master. When one is sufficiently trained and acts in submissive faith and love for Kṛṣṇa under the direction of the bona fide spiritual master, the dovetailing process becomes more firm and accurate. This stage of devotional service by the devotee in Kṛṣṇa consciousness is the most perfect stage of the yoga system. At this stage, Kṛṣṇa, or the Supersoul, dictates from within, while from without the devotee is helped by the spiritual master, who is the bona fide representative of Kṛṣṇa. From within He helps the devotee as caitya, for He is seated within the heart of everyone. Understanding that God is seated within everyone's heart is not, however, sufficient. One has to be acquainted with God from both within and without, and one must take dictation from within and without to act in Kṛṣṇa consciousness. This is the highest perfectional stage of the human form of life and the topmost perfection of all yoga.
(Srimad Bhagavatam----3:15:45----purport).

Kṛṣṇa is so kind and affectionate toward His devotees that He helps them by giving them the intelligence by which to exist in this material world without forgetting Him even for a moment. The Lord says:
teṣām evānukampārtham
aham ajñāna-jaṁ tamaḥ
nāśayāmy ātma-bhāvastho
jñāna-dīpena bhāsvatā
"Out of compassion for them, I, dwelling in their hearts, destroy with the shining lamp of knowledge the darkness born of ignorance." (B.G.10:11)
The word yoga means "link." Any system of yoga is an attempt to reconnect our broken relationship with the Supreme Personality of Godhead. There are different types of yoga, of which bhakti-yoga is the best. In other yoga systems, one must undergo various processes before attaining perfection, but bhakti-yoga is direct.
(Srimad Bhagavatam----10:2:6----purport).

If a devotee at all wants to cleanse his heart, he must chant and hear the glories of the Lord, Śrī Kṛṣṇa (śṛṇvatāṁ sva-kathāḥ kṛṣṇaḥ (S.B.1:2:17). This is a simple process. Kṛṣṇa Himself will help cleanse the heart because He is already seated there. Kṛṣṇa wants to continue living within the heart, and the Lord wants to give directions, but one has to keep his heart as clean as Lord Caitanya Mahāprabhu kept the Guṇḍicā temple. The devotee therefore has to cleanse his heart just as the Lord cleansed the Guṇḍicā temple. In this way one can be pacified and enriched in devotional service. If the heart is filled with straw, grains of sand, weeds or dust (in other words, anyābhilāṣa-pūrṇa), one cannot enthrone the Supreme Personality of Godhead there. The heart must be cleansed of all material motives brought about through fruitive work, speculative knowledge, the mystic yoga system and so many other forms of so-called meditation. The heart must be cleansed without ulterior motive.
(Sri Caitanya Caritamrta----2:12:135----purport).

As stated in the Bhagavad-gītā (18.61), īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati. Staying within everyone's heart, Lord Kṛṣṇa works very gravely. No one can understand how He is working, but as soon as the Lord understands the sincere activity of a person in devotional service, He helps him in such a way that the devotee cannot understand how things are happening. If the devotee is determined to serve the Lord, the Lord is always prepared to help him (dadāmi buddhi-yogaṁ taṁ yena mām upayānti te). Śrī Caitanya Mahāprabhu is telling Sanātana Gosvāmī how merciful the Lord is. Sanātana Gosvāmī was a minister in the service of Nawab Hussain Shah. He was always mixing with materially inclined people, particularly with Muslims, meat-eaters. Although he was in intimate touch with them, by Kṛṣṇa's mercy he came to find such association distasteful. Therefore he left them. As stated by Śrīnivāsa Ācārya, tyaktvā tūrṇam aśeṣa-maṇḍala-pati-śreṇīṁ sadā tuccha-vat. Kṛṣṇa enlightened Sanātana Gosvāmī in such a way that he was able to give up his exalted post as minister. Thinking his material position insignificant, Sanātana was prepared to become a mendicant. Appreciating the activities of Sanātana Gosvāmī, Śrī Caitanya Mahāprabhu praised his action and thanked Kṛṣṇa for His mercy upon him.
(Sri Caitanya Caritamrta----2:20:63----purport).

"To those who are constantly devoted and worship Me with love, I give the understanding by which they can come to Me." Kṛṣṇa does not become the direct spiritual master unless one is fully trained by His representative spiritual master. Therefore, as we have already discussed, the Lord's representative spiritual master should not be considered an ordinary human being. The representative spiritual master never gives any false knowledge to his disciple, but only perfect knowledge. Thus he is the representative of Kṛṣṇa. Kṛṣṇa helps as the guru, or spiritual master, from within and from without. From without He helps the devotee as His representative, and from within He talks personally with the pure devotee and gives him instructions by which he may return home, back to Godhead.
(Srimad Bhagavatam----7:15:76----purport).

A devotee is inspired by the Supersoul within the heart to advance in devotional service in a variety of ways. The devotee does not feel hackneyed or stereotyped, nor does he feel that he is in a stagnant position. In the material world, if one engages in chanting a material name, he will feel tired after chanting a few times. However, one can chant the Hare Kṛṣṇa mahā-mantra all day and night and never feel tired. As chanting is increased, it will come out new and fresh. Śrīla Rūpa Gosvāmī said that if he could somehow get millions of ears and tongues, then he could relish spiritual bliss by chanting the Hare Kṛṣṇa mahā-mantra. There is really nothing uninspiring for a highly advanced devotee. In Bhagavad-gītā the Lord says that He is situated in everyone's heart and that He helps the living entity forget and remember. By the grace of the Lord, the devotee gets inspiration.
(Srimad Bhagavatam----4:30:20----purport).