Srimad Bhagavatam Canto 08, Chapter 16, Text 23

SB 8.16.23

adisa tvam dvija-srestha
 vidhim tad-upadhavanam
asu tusyati me devah
 sidantyah saha putrakaih
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
O best of the brahmanas, 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.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
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-gita, where Arjuna accepted Krsna as his guru (sisyas te ’ham sadhi mam tvam prapannam). The Vedas also instruct, tad-vijñanartham sa gurum evabhigacchet: 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 acarya, who is the representative of the Supreme Personality of Godhead (acaryam mam vijaniyat). One should definitely understand this. In Caitanya-caritamrta it is said that the guru is the manifestation of the Supreme Personality of Godhead. Therefore, according to all the evidence given by the sastra 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.
Srimad Bhagavatam Canto 08, Chapter 16, Text 22
Srimad Bhagavatam Canto 08, Chapter 16, Text 24