In the Śrīmad-Bhāgavatam (1.5.17) Śrī Nārada Muni instructs Vyāsadeva as follows:
tyaktvā sva-dharmaṁ caraṇāmbujaṁ harer
bhajann apakvo 'tha patet tato yadi
yatra kva vābhadram abhūd amuṣya kiṁ
ko vārtha āpto 'bhajatāṁ sva-dharmataḥ
"If someone gives up all material prospects and takes complete shelter of the Supreme Personality of Godhead, there is no loss or degradation in any way. On the other hand a nondevotee may fully engage in his occupational duties and yet not gain anything."
(Bhagavad-Gita----6:40----purport).

"Devotional service is so potent that simply by engaging in the activities of devotional service one becomes enlightened without a doubt." A practical example of this can be seen in the previous life of Nārada, who in that life happened to be the son of a maidservant. He had no education, nor was he born into a high family. But when his mother was engaged in serving great devotees, Nārada also became engaged, and sometimes, in the absence of his mother, he would serve the great devotees himself.
(Bhagavad-Gita----9:2----purport).

Nārada personally says,
ucchiṣṭa-lepān anumodito dvijaiḥ
sakṛt sma bhuñje tad-apāsta-kilbiṣaḥ
evaṁ pravṛttasya viśuddha-cetasas
tad-dharma evātma-ruciḥ prajāyate
In this verse from Śrīmad-Bhāgavatam (1.5.25) Nārada describes his previous life to his disciple Vyāsadeva. He says that while engaged as a boy servant for those purified devotees during the four months of their stay, he was intimately associating with them. Sometimes those sages left remnants of food on their dishes, and the boy, who would wash their dishes, wanted to taste the remnants. So he asked the great devotees for their permission, and when they gave it Nārada ate those remnants and consequently became freed from all sinful reactions. As he went on eating, he gradually became as pure-hearted as the sages. The great devotees relished the taste of unceasing devotional service to the Lord by hearing and chanting, and Nāradagradually developed the same taste. Nārada says further,
tatrānvahaṁ kṛṣṇa-kathāḥ pragāyatām
anugraheṇāśṛṇavaṁ manoharāḥ
tāḥ śraddhayā me 'nupadaṁ viśṛṇvataḥ
priyaśravasy aṅga mamābhavad ruciḥ
By associating with the sages, Nārada got the taste for hearing and chanting the glories of the Lord, and he developed a great desire for devotional service. Therefore, as described in the Vedānta-sūtra, prakāśaś ca karmaṇy abhyāsāt: if one is engaged simply in the acts of devotional service, everything is revealed to him automatically, and he can understand. This is called pratyakṣa, directly perceived.
The word dharmyam means "the path of religion."
(Bhagavad-Gita----9:2----purport).

Nārada was actually a son of a maidservant. He had no opportunity to go to school. He was simply assisting his mother, and fortunately his mother rendered some service to the devotees. The child Nārada also got the opportunity and simply by association achieved the highest goal of all religion. The highest goal of all religion is devotional service, as stated in Śrīmad-Bhāgavatam (sa vai puṁsāṁ paro dharmo yato bhaktir adhokṣaje). Religious people generally do not know that the highest perfection of religion is the attainment of devotional service. As we have already discussed in regard to the last verse of Chapter Eight (vedeṣu yajñeṣu tapaḥsu caiva), generally Vedic knowledge is required for self-realization. But here, although Nārada never went to the school of the spiritual master and was not educated in the Vedic principles, he acquired the highest results of Vedic study. This process is so potent that even without performing the religious process regularly, one can be raised to the highest perfection. How is this possible? This is also confirmed in Vedic literature: ācāryavān puruṣo veda. One who is in association with great ācāryas, even if he is not educated or has never studied the Vedas, can become familiar with all the knowledge necessary for realization.
(Bhagavad-Gita----9:2----purport).

The banyan tree (aśvattha) is one of the highest and most beautiful trees, and people in India often worship it as one of their daily morning rituals. Amongst the demigods they also worshipNārada, who is considered the greatest devotee in the universe. Thus he is the representation of Kṛṣṇa as a devotee.
(Bhagavad-Gita----10:26----purport).

Vyāsadeva compiled all Vedic literatures, containing the four divisions of the Vedas, the Vedānta-sūtras (or the Brahma-sūtras), the Purāṇas, the Mahābhārata, and so on. But nevertheless he was not satisfied. His dissatisfaction was observed by his spiritual master, and thus Nārada advised him to write on the transcendental activities of Lord Śrī Kṛṣṇa.
(Srimad Bhagavatam----1:1:1----purport).

Śrīmad-Bhāgavatam is exactly received from the right source. It was brought by Nārada Muni from the spiritual world and given to his disciple Śrī Vyāsadeva.
(Srimad Bhagavatam----1:1:3----purport).

The great Ṛṣi Nārada, who is an empowered incarnation of the Personality of Godhead, propagates devotional service all over the universe. All great devotees of the Lord all over the universe and in different planets and species of life are his disciples. Śrīla Vyāsadeva, the compiler of the Śrīmad-Bhāgavatam, is also one of his disciples. Nārada is the author of Nārada-pañcarātra, which is the exposition of the Vedas particularly for the devotional service of the Lord. This Nārada-pañcarātra trains the karmīs, or the fruitive workers, to achieve liberation from the bondage of fruitive work. The conditioned souls are mostly attracted by fruitive work because they want to enjoy life by the sweat of their own brows. The whole universe is full of fruitive workers in all species of life. The fruitive works include all kinds of economic development plans. But the law of nature provides that every action has its resultant reaction, and the performer of the work is bound up by such reactions, good or bad. The reaction of good work is comparative material prosperity, whereas the reaction of bad work is comparative material distress. But material conditions, either in so-called happiness or in so-called distress, are all meant ultimately for distress only. Foolish materialists have no information of how to obtain eternal happiness in the unconditional state. Śrī Nārada informs these foolish fruitive workers how to realize the reality of happiness. He gives direction to the diseased men of the world how one's present engagement can lead one to the path of spiritual emancipation. The physician directs the patient to take treated milk in the form of curd for his sufferings from indigestion due to his taking another milk preparation. So the cause of the disease and the remedy of the disease may be the same, but it must be treated by an expert physician like Nārada. The Bhagavad-gītā also gives the same solution of serving the Lord by the fruits of one's labor. That will lead one to the path of naiṣkarmya, or liberation.
(Srimad Bhagavatam----1:3:8----purport).

Śrī Nārada is empowered with devotional service.
(Srimad Bhagavatam----1:3:26----purport).