Arjuna was in a relationship with the Lord as friend. Of course there is a gulf of difference between this friendship and the friendship found in the material world. This is transcendental friendship, which cannot be had by everyone. Of course everyone has a particular relationship with the Lord, and that relationship is evoked by the perfection of devotional service. But in the present status of our life, not only have we forgotten the Supreme Lord, but we have forgotten our eternal relationship with the Lord. Every living being, out of the many, many billions and trillions of living beings, has a particular relationship with the Lord eternally. That is called svarūpa. By the process of devotional service, one can revive that svarūpa, and that stage is called svarūpa-siddhi—perfection of one's constitutional position. So Arjuna was a devotee, and he was in touch with the Supreme Lord in friendship.
How Arjuna accepted this Bhagavad-gītā should be noted. His manner of acceptance is given in the Tenth Chapter (10.12-14):
- arjuna uvāca
- paraṁ brahma paraṁ dhāma
- pavitraṁ paramaṁ bhavān
- puruṣaṁ śāśvataṁ divyam
- ādi-devam ajaṁ vibhum
- āhus tvām ṛṣayaḥ sarve
- devarṣir nāradas tathā
- asito devalo vyāsaḥ
- svayaṁ caiva bravīṣi me
- sarvam etad ṛtaṁ manye
- yan māṁ vadasi keśava
- na hi te bhagavan vyaktiṁ
- vidur devā na dānavāḥ
"Arjuna said: You are the Supreme Personality of Godhead, the ultimate abode, the purest, the Absolute Truth. You are the eternal, transcendental, original person, the unborn, the greatest. All the great sages such as Nārada, Asita, Devala, and Vyāsa confirm this truth about You, and now You Yourself are declaring it to me. O Kṛṣṇa, I totally accept as truth all that You have told me. Neither the demigods nor the demons, O Lord, can understand Your personality."
After hearing Bhagavad-gītā from the Supreme Personality of Godhead, Arjuna accepted Kṛṣṇa as paraṁ brahma, the Supreme Brahman. Every living being is Brahman, but the supreme living being, or the Supreme Personality of Godhead, is the Supreme Brahman. Paraṁ dhāma means that He is the supreme rest or abode of everything; pavitram means that He is pure, untainted by material contamination; puruṣam means that He is the supreme enjoyer; śāśvatam, original; divyam, transcendental; ādi-devam, the Supreme Personality of Godhead; ajam, the unborn; and vibhum, the greatest.
Now one may think that because Kṛṣṇa was the friend of Arjuna, Arjuna was telling Him all this by way of flattery, but Arjuna, just to drive out this kind of doubt from the minds of the readers of Bhagavad-gītā, substantiates these praises in the next verse when he says that Kṛṣṇa is accepted as the Supreme Personality of Godhead not only by himself but by authorities like Nārada, Asita, Devala and Vyāsadeva. These are great personalities who distribute the Vedic knowledge as it is accepted by all ācāryas. Therefore Arjuna tells Kṛṣṇa that he accepts whatever He says to be completely perfect. Sarvam etad ṛtaṁ manye: "I accept everything You say to be true." Arjuna also says that the personality of the Lord is very difficult to understand and that He cannot be known even by the great demigods. This means that the Lord cannot even be known by personalities greater than human beings. So how can a human being understand Lord Śrī Kṛṣṇa without becoming His devotee?
Therefore Bhagavad-gītā should be taken up in a spirit of devotion. One should not think that he is equal to Kṛṣṇa, nor should he think that Kṛṣṇa is an ordinary personality or even a very great personality. Lord Śrī Kṛṣṇa is the Supreme Personality of Godhead. So according to the statements of Bhagavad-gītā or the statements of Arjuna, the person who is trying to understand the Bhagavad-gītā, we should at least theoretically accept Śrī Kṛṣṇa as the Supreme Personality of Godhead, and with that submissive spirit we can understand the Bhagavad-gītā. Unless one reads the Bhagavad-gītā in a submissive spirit, it is very difficult to understand Bhagavad-gītā, because it is a great mystery.