"Locana Dasa Thakura declares that the two Lords, Nitai-Gauracandra-- Lord Nitai and Lord Caitanya -- are very merciful (parama karuna). Saba avatara-sara siromani. Avatara means 'incarnation,' and saba means 'all.' They are the essence of all incarnations. The specific significance of these incarnations is that prosecuting Their way of self-realization is simply joyful (kevala ananda-kanda), for They introduced chanting and dancing. There are many incarnations, like Lord Rama and even Krsna, who taught Bhagavad-gita, which requires knowledge and understanding. But Lord Caitanya and Nityananda introduced a process that is simply joyful -- simply chant and dance. Therefore, Locana Dasa requests everyone, bhajo bhajo bhai, caitanya-nitai: 'My dear brother, I request that you just worship Lord Caitanya and Nityananda with firm conviction and faith.' Don't think that this chanting and dancing will not lead to the desired goal. It will. It is the assurance of Lord Caitanya Mahaprabhu that one will get all perfection by this process. Therefore one must chant with firm faith and conviction (biswasa kori)."
(From Sri Sri Gaura-Nityanander Daya by Locana Dasa Thakura, Purport by Srila Prabhupada)