Yad advaitam brahmopanisadi tad apy asya tanu-bha/ya atmantaryami purusa iti so ‘syamsa-vibhavah/sad-aisvaryaih purno ya iha bhagavan sa svayam ayam/na caitanyat krsnaj jagati para-tattvam param iha
‘What the Upanisads describe as the impersonal Brahman is but the effulgence of his body, and the Lord known as the Supersoul is but His localized plenary portion. He is the Supreme Personality of Godhead, Krsna Himself, full with six opulences. He is the Absolute Truth, and no other truth is greater than or equal to Him’
[Sri Caitanya-Caritamrita, Adi-lila 1.3 (verse three of the 14 verse mangalacarana or introductory invocation]
Sri Caitanya Caritamrita, Adi-Lila, Chapter 2, is basically a lengthy purport to this third verse of the mangalacarana . Krishna Das Kaviraja Maharaja argues that Lord Chaitanya is none other than Krishna Himself – or Narayana (not Vaikuntha Narayana, but Krishna who is also called Narayana). A.C. Bhaktivedanta Swami Prabhupada has, therefore, aptly entitled this chapter: ‘Sri Caitanya Mahaprabhu, the Supreme Personality of Godhead’.
The Vaishnava acaryas (spiritual masters) are always trying to establish the siddhanta (spiritual conclusions) of the guru-parampara. The word parampara means ‘chain’. The guru-parampara is an unbroken “chain” or line of spiritual preceptors that goes all the way back to the original spiritual master, or guru – Lord Krishna. Hence the saying, ‘Guru is one’. In other words, the guru simply represents Krishna and Krishna’s teachings. Krishna and His representatives (the guru-parampara) try to establish, amongst other things, Krishna’s position as the Supreme Personality of Godhead; the supremacy of devotional service; and the authenticity of the disciplic succession.
Krishna Das Kaviraja Maharaja begins his argument in Adi-Lila 2.9: ‘He whom Srimad Bhagavatam (SB) describes as the son of Nanda Maharaja has descended to earth as Lord Caitanya.’ CC Adi-Lila Chapter 2 gives the supporting argument to this statement. In order to establish that Mahaprabhu is the Supreme Personality of Godhead, Kaviraja Maharaja has to establish Krishna as the Supreme Personality of Godhead.
Krishna Das Kaviraja describes the three features of the Lord, as they appear in Verse 3 of the mangalacarana: Brahman, Paramatma and Bhagavan. He also quotes SB 1.2.11: vadanti tat tattva-vidas/tattvam yaj jnanam advayam/brahmeti paramatmeti/bhagavan iti sabdyate: ‘Learned transcendentalists who know the Absolute Truth say that it is nondual knowledge and is called impersonal Brahman, localized Paramatma and the Personality of Godhead.’ He then proceeds, quoting scripture, to distinguish the incomplete realizations of the Absolute truth, Brahman and Paramatma, from the complete realization, namely Bhagavan.