- Bhakti saints are broadly classified into two schools: Nirguna (worshipping a formless God) and Saguna (worshipping God with form). - Kabir, Guru Nanak (founder of Sikhism), and Dadu Dayal belonged to the Nirguna school, emphasizing a formless, omnipresent God and often criticizing idolatry and caste distinctions. - Chaitanya Mahaprabhu (1486–1534) was a prominent saint of the Saguna school, specifically a devotee of Lord Krishna. He is credited with popularizing the Hare Krishna mantra and the Gaudiya Vaishnavism tradition.