Symbolism, Imagery, Allegory
Three Bibles are among the wreckage of the ship. The Bible is hugely important for Crusoe's time on the island, as it will serve as his moral compass and means of spiritual reformation.
…also I found three very good Bibles which came to me in my Cargo from England, and which I had pack'd up among my things. (56)
The book is a symbol of Crusoe's connection to God and later becomes a tool with which to teach Friday the basics of Christianity.