Sri Chaitanya Mahaprabhu showed by his personal life the validity of the doctrines of devotion described in Srimad Bhagavata. Holding Achintya-Bheda-bheda or identity-in-difference to be the nature of the Ultimate Reality whom he called Sri Krishna, Chaitanya demonstrated how Bhakti is the sure way to higher spiritual development.
All that is real in me is God; all that is real in God is I. The gulf between God and human beings is thus bridged. Thus we find how, by knowing God, we find the kingdom of heaven within us.
-Swami Vivekananda