Christians. Christ called John the Baptist, who came with the spirit of Elijah, the greatest born of women...?

and a blazing lamp of the Spirit. In fact, no greater prophet had lived. Now this is a question that requires thought (and I am Christian): How could John be the greatest of the prophets if he spoke nothing unique? Remember, Isaiah said Christ would be as a lamb and carry the sins of the people. Isaiah explained much more in prophecy about both comings of Christ than the few words John said. The other prophets also died for what they believed. And the other prophets wrote books which were added to the Tanakh (Old Testament). Where is John's great book of prophecy with the greatest prophecies?