Srimad Bhagavatam Canto 04, Chapter 29, Text 50

SB 4.29.50

harir deha-bhrtam atma
 svayam prakrtir isvarah
tat-pada-mulam saranam
 yatah ksemo nrnam iha
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
Sri Hari, the Supreme Personality of Godhead, is the Supersoul and guide of all living entities who have accepted material bodies within this world. He is the supreme controller of all material activities in material nature. He is also our best friend, and everyone should take shelter at His lotus feet. In doing so, one’s life will be auspicious.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
In Bhagavad-gita (18.61) it is said, isvarah sarva-bhutanam hrd-dese ’rjuna tisthati: “The Supreme Lord is situated in everyone’s heart, O Arjuna.” The living entity is within the body, and the Supersoul, the Supreme Personality of Godhead, is also there. He is called antaryami and caitya-guru. As Lord Krsna states in Bhagavad-gita (15.15), He is controlling everything:
sarvasya caham hrdi sannivisto
 mattah smrtir jñanam apohanam ca
“I am seated in everyone’s heart, and from Me come remembrance, knowledge and forgetfulness.”
Everything is being directed by the Supersoul within the body; therefore the better part of valor is to take His direction and be happy. To take His directions, one needs to be a devotee, and this is also confirmed in Bhagavad-gita (10.10):
tesam satata-yuktanam
 bhajatam priti-purvakam
dadami buddhi-yogam tam
 yena mam upayanti te
“To those who are constantly devoted and worship Me with love, I give the understanding by which they can come to Me.”
Although the Supersoul is in everyone’s heart (isvarah sarva-bhutanam hrd-dese ’rjuna tisthati), He talks only to the pure devotees who constantly engage in His service. In Caitanya-bhagavata (Antya 3.45) it is said:
tahare se bali vidya, mantra, adhyayana
 krsna-pada-padme ye karaye sthira mana
“One who has fixed his mind on the lotus feet of Krsna is to be understood as having the best education and as having studied all the Vedas.” There are also other appropriate quotes in Caitanya-bhagavata:
sei se vidyara phala janiha niscaya
 krsna-pada-padme yadi citta-vrtti raya
“The perfect result of an education is the fixing of one’s mind on the lotus feet of Krsna.” (Adi 13.178)
‘dig-vijaya kariba,’ — vidyara karya nahe
 isvare bhajile, sei vidya ‘satya’ kahe
“Conquering the world by means of material education is not desirable. If one engages himself in devotional service, his education is perfected.” (Adi 13.173)
pade kene loka — krsna-bhakti janibare
 se yadi nahila, tabe vidyaya ki kare
“The purpose of education is to understand Krsna and His devotional service. If one does not do so, then education is false.” (Adi 12.49)
tahare se bali dharma, karma sadacara
 isvare se priti janme sammata sabara
“Being cultured, educated, very active and religious means developing natural love for Krsna.” (Antya 3.44) Everyone has dormant love for Krsna, and by culture and education that has to be awakened. That is the purpose of this Krsna consciousness movement. Once Lord Caitanya asked Sri Ramananda Raya what the best part of education was, and Ramananda Raya replied that the best part of education is advancement in Krsna consciousness.
Srimad Bhagavatam Canto 04, Chapter 29, Text 49
Srimad Bhagavatam Canto 04, Chapter 29, Text 51