Lord Caitanya came to earth simply to preach kṛṣṇa-bhakti, love of Kṛṣṇa. In other words, He is Lord Kṛṣṇa Himself teaching the living entities the proper way to approach Kṛṣṇa. He is like a teacher who, seeing a student doing poorly, takes up a pencil and writes, saying, "Do it like this: A, B, C." From this one should not foolishly think that the teacher is learning his ABC's. Similarly, although Lord Caitanya appears in the guise of a devotee, we should not foolishly think He is an ordinary human being; we should always remember that Lord Caitanya is Kṛṣṇa (God) Himself teaching us how to become Kṛṣṇa conscious, and we must study Him in that light.