Sri Chaitanya Mahaprabhu preached the Srimad-Bhagavatam and propagated the teachings of the Bhagavad-Gita in the most practical way. The essence of His teachings is recorded in Chaitanya Manjusha as follows:
Lord Sri Krishna, who appeared as the son of the King of Vraja (Nanda Maharaja), is the Supreme Personality of Godhead and is worshipable by all.
Vrindavana-dhama is non-different from the Lord and hence is as worshipable as the Lord.
The highest form of transcendental worship of the Lord was exhibited by the damsels of Vrajabhumi.
Srimad-Bhagavata Purana is the spotless literature for understanding the Lord.
The ultimate goal of human life is to attain the stage of prema or love of God.
His instructions to Srila Rupa Gosvami and Srila Sanatana Gosvami, His discussions with Ramananda Raya, the debate with the Mayavadi sannyasi Prakashananda Sarasvati and the Vedanta Sutra, the discussion between Him and Sarvabhauma Bhattacharya are excellent sources through which we understand His teachings in detail.
The Lord left only eight slokas of His instructions in writing, and they are known as the Siksastaka. All other literatures based on His teachings were extensively written by the Lord’s principal followers, the six Gosvamis of Vrindavana, and their followers.