I discovered drops of blood on the corn as though it were dew from heaven—and I communicated it to many, both white and black, in the neighborhood—and I then found on the leaves in the woods hieroglyphic characters, and numbers, with the forms of men in different attitudes, portrayed in blood, and representing the figures I had seen before in the heavens. And now the Holy Ghost had revealed itself to me, and made plain the miracles it had shown me—For as the blood of Christ had been shed on this earth, and had ascended to heaven for the salvation of sinners, and was now returning to earth again in the form of dew—and as the leaves on the trees bore the impression of the figures I had seen in the heavens, it was plain to me that the Saviour was about to lay down the yoke he had borne for the sins of men, and the great day of judgment was at hand.
If there were truly drops of blood, it may very well have been the blood from fellow slaves, and the drawings on leaves may have also been a product of fellow slaves in their quest for freedom. I believe that Nat Turner was very knowledgeable of Christ and used his knowledge to persuade others into supporting/following him; he was able to relate everyday findings to the history of Christ in some way that most slaves would be familiar with. Similar to Jonathan Edwards and others that were part of the Great Awakening, Turner appealed to the religious slaves who dared not question God.