Srimad-Bhagavatam: Canto 8 - Chapter 1 - Verse 23
आदिश त्वं द्विजश्रेष्ठ विधिं तदुपधावनम् ।आशु तुष्यति मे देव: सीदन्त्या: सह पुत्रकै: ॥ २३ ॥
ādiśa tvaṁ dvija-śreṣṭhavidhiṁ tad-upadhāvanamāśu tuṣyati me devaḥsīdantyāḥ saha putrakaiḥ
O best of the brāhmaṇas, kindly instruct me in the perfect method of worshiping the Supreme Personality of Godhead in devotional service, by which the Lord may very soon be pleased with me and save me, along with my sons, from this most dangerous condition.
Sometimes less intelligent men ask whether one has to approach a guru to be instructed in devotional service for spiritual advancement. The answer is given here — indeed, not only here, but also in Bhagavad-gītā, where Arjuna accepted Kṛṣṇa as his guru (śiṣyas te ’haṁ śādhi māṁ tvāṁ prapannam). The Vedas also instruct, tad-vijñānārthaṁ sa guruṁ evābhigacchet: one must accept a guru for proper direction if one is seriously inclined toward advancement in spiritual life. The Lord says that one must worship the ācārya, who is the representative of the Supreme Personality of Godhead (ācāryaṁ māṁ vijānīyāt). One should definitely understand this. In Caitanya-caritāmṛta it is said that the guru is the manifestation of the Supreme Personality of Godhead. Therefore, according to all the evidence given by the śāstra and by the practical behavior of devotees, one must accept a guru. Aditi accepted her husband as her guru, so that he would direct her how to advance in spiritual consciousness, devotional service, by worshiping the Supreme Lord.