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.
Mind you, this is life's experience: if you really want the good of others, the whole universe may stand against you and cannot hurt you. It must crumble before your power of the Lord Himself in you if you are sincere and really unselfish.
-Swami Vivekananda