PURPORT

isvarah sarva-bhutanam
hrd-dese 'rjuna tisthati
bhramayan sarva-bhutani
yantrarudhani mayaya

"The Supreme Lord is situated in everyone's heart, O Arjuna, and is directing the wanderings of all living entities, who are seated as on a machine, made of the material energy." (Bg. 18.61)

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, He is controlling everything.

sarvasya caham hrdi sannivisto
mattah smrtir jnanam apohanam ca
vedais ca sarvair aham eva vedyo
vedanta-krd veda-vid eva caham

"I am seated in everyone's heart, and from Me come remembrance, knowledge and forgetfulness. By all the Vedas am I to be known; indeed I am the compiler of Vedanta, and I am the knower of the Vedas." (Bg. 15.15)

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:

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." (Bg. 10.10)

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 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." (Cb. Antya 3.45) 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." (Cb. 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." (Cb. 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." (Cb. 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." (Cb. 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.