"Sakhyam. In regard to worshiping the Lord as a friend, the Agastya-samhita states that a devotee engaged in performing devotional service by sravanam and kirtanam sometimes wants to see the Lord personally, and for this purpose he resides in the temple. Elsewhere there is this statement: "O my Lord, Supreme Personality and eternal friend, although You are full of bliss and knowledge, You have become the friend of the residents of Vrndavana. How fortunate are these devotees!" In this statement the word "friend" is specifically used to indicate intense love. Friendship, therefore, is better than servitude. In the stage above dasya-rasa, the devotee accepts the Supreme Personality of Godhead as a friend. This is not at all astonishing, for when a devotee is pure in heart the opulence of his worship of the Deity diminishes as spontaneous love for the Personality of Godhead is manifested. In this regard, Sridhara Svami mentions Sridama Vipra, who expressed to himself his feelings of obligation, thinking, "Life after life, may I be connected with Krsna in this friendly attitude."
"According to the opinion of advanced devotees and learned scholars, a devotee in sakhya-rati feels equal to the Supreme Personality of Godhead. This is a relationship in friendship. Due to having a friendly relationship with the Lord, not only is one free from material attachment, but one believes in equal dealings with the Supreme Personality of Godhead. This is called sakhya-rati. The sakhya-rati devotee is so advanced that he treats the Lord on an equal level and even exchanges joking words. Although one is never equal to the Supreme Personality of Godhead, the sakhya-rati devotee feels equal to the Lord, and he does not feel guilty because of this. Actually it is offensive to consider oneself equal to the Lord. The Mayavadis consider themselves equal to the Lord, but such feelings entail bereavement because they are material. The sakhya-rati, however, is a feeling experienced in the mind by a pure devotee, and he is eternally related with the Supreme Personality of Godhead in that feeling."
Caitanya-caritamrta, Madyam lila 19:18
"Devotional service in friendship can be divided into two categories: the first is to act as the confidential servant of the Lord, and the other is to act as the well-wisher of the Lord. The devotee who has confidence in devotional service to the Lord systematically follows the rules and regulations, with the faith that lie will achieve the platform of transcendental life. The second type of devotional friendship is to become a well-wisher of the Supreme Personality of Godhead. In Bhagavad-gita it is said that the Lord accepts a preacher as the most dear servant. Anyone who is preaching the confidential message of the Gita to the people in general is so dear to Krsna that no one can be equal to him in human society.
In the Mahabharata, Draupadi says, "My dear Govinda, Your promise is that Your devotee can never be vanquished. I believe in that statement, and therefore in all kinds of tribulations I simply remember Your promise, and thus I live." The purport is that Draupadi and her five husbands, the Pandavas, were put into severe tribulations by their cousin-brother Duryodhana, as well as by others. The tribulations were so severe that even Bhismadeva, who was both a lifelong brahmacari and a great warrior, would sometimes shed tears thinking of them. He was always surprised that although the Pandavas were so righteous and Draupadi was practically the goddess of fortune, and although Krsna was their friend, still they had to undergo such severe tribulations. Though their tribulations were not ordinary, Draupadi was not discouraged. She knew that because Krsna was their friend, ultimately they would be saved.
A similar statement is there in the Eleventh Canto of Srimad-Bhagavatam, Second Chapter, verse 53, where Havi, the son of King Rsabha, addresses Maharaja Nimi: "My dear King, a person who never deviates even for a moment from engagement in service at the lotus feet of the Supreme Person (engagement which is sought even by great demigods like Indra), with firm conviction that there is nothing more worshipable or desirable than this, is called the first-class devotee."
Sri Rupa Gosvami says that a neophyte devotee who has simply developed a slight love of Godhead is certainly a prospective candidate for devotional service. When he becomes firmly fixed in such devotional service, that assured status becomes a confidential part of his devotional service.
Sometimes it is found that a pure devotee lies down in the temple of the Lord in order to serve Him as a confidential friend. Such friendly behavior of a devotee may be accepted as raganuga, or spontaneous. Although, according to regulative principles, no one can lie down in the temple of the Supreme Personality of Godhead, this spontaneous love of Godhead may be grouped under devotional service in friendship."
Nectar of Devotion, Chapter 10
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.