Sri Nityananda Trayodashi is the auspicious appearance day of Nityananda Prabhu. Lord Nityananda Prabhu appeared as Lord Chaitanya’s principal associate for spreading the congregational chanting of the holy names of God. He especially spread the holy names of Krishna throughout Bengal. The Supreme Lord Sri Krishna appeared in Navadvipa as Sri Chaitanya Mahaprabhu to establish the Sankirtana Movement (the yuga dharma for this age of quarrel and hypocrisy). To help the Supreme Lord in His mission, Lord Balarama appeared as Nityananda Prabhu.
Nityananda Prabhu is an eternal associate of Sri Chaitanya Mahaprabhu. Vaishnava acharyas emphatically state that people who try to understand Chaitanya Mahaprabhu without getting the mercy of Nityananda Prabhu will never succeed and one must pray very sincerely to Lord Nityananda Prabhu as the adi-guru (original spiritual master) to be delivered to the Lotus feet of Sri Chaitanya Mahaprabhu.
Nevertheless He is considered more merciful than Lord Caitanya because He is so eager to deliver the mercy of Lord Caitanya. If anyone can please Nitai even in the smallest way, then that person will receive a spiritual grace that will transform his life.
Devotees fast until noon on Nityananda-trayodasi and gather at Sri Narasimha Giridhari Mandir to relish this very wonderful festival. Their Lordships are decorated gorgeously with colorful flowers and new festival outfits. Nityananda Prabhu’s pastimes from Sri Chaitanya-Bhagavata are narrated. The kirtana plunges everyone into an ocean of transcendental bliss. A feast is then served to mark this glorious occasion.