What was the reason of birth of Chaitanya Mahaprabhu being an avatar of god he was not able to create huge impact on the world instead almost negligible people in the world today know him whereas common leaders of other dharmas are worldwide famous.Just born to be enlightened.This creates a doubt whether he was really an avatar of God.Neither his teachings exits nor his complete story and why was he born???
The reasons for Sri Caitanya's appearance are given in Śrī Caitanya-caritāmṛta Ādi-līlā 3.19/20
yuga-dharma pravartāimu nāma-saṅkīrtana
cāri bhāva-bhakti diyā nācāmu bhuvana
āpani karimu bhakta-bhāva aṅgīkāre
āpani ācari’ bhakti śikhāimu sabāre
I shall personally inaugurate the religion of the age — nāma-saṅkīrtana, the congregational chanting of the holy name. I shall make the world dance in ecstasy, realizing the four mellows of loving devotional service. I shall accept the role of a devotee, and I shall teach devotional service by practicing it Myself.