On page 3 of the prologue the reader is abruptly assaulted by the a contextual set-up from the narrator when he explains the Visitor having said; 

“Hope is the last resort of the Faithless.”

This single line on page 3 of the prologue is not only a contextual glimpse of who the visitor is, but is some very heavy foreshadowing of future books coming in The Corvus Chronicles.

The visitor is even described "as hopeless" in the literal sense that he does not believe in hope.  The constant cascading disappointments carved out the need for the visitor to gravitate towards a stronger comfort, and that comfort is found in Faith.  In essence; the visitor replaced hope with Faith.

This concept can rightfully be unsettling.  People tend to think of hope as a good thing.  But the meanings of word have become so watered down that words can become useless.  This is a central theme spoken by the visitor in wishing that he could speak in a universal language requiring no words.  On the chapter on Love he describes how the word Love itself has become meaningless, as it no longer is used to describe a "sacred" relationship, but rather to describe mundane things, like how someone "loves chocolate or loves wine".  

Arguments about hope might start from a "sacred" source such as Corinthians 1:

As it is, these remain: faith, hope and love, the three of them; and the greatest of them is love, but the salient point that is missed by too many, is that in the Bible hope is used to convey a sacred concept.  It is not used in mundane connotations such as "hoping to win the lottery, or hoping to get a raise, or hoping my child gets better".   The hope which the visitor references is "hope" used in a non-sacred sense.

Notwithstanding how the visitor is described as hopeless, the visitor admits that he sees how hope may serve as "the seeds of Faith".  However, he also clarifies that hope is not Faith.  This distinction is pretty self-evident but can be illustrated even better by again turning towards the Bible; this time Hebrews 11:1

Now faith is the substance of things hoped for, the evidence of things not seen.

In essence, the visitor trades hope for faith, because faith is the actual substance of things hoped for.  The evidence of things not seen is from the Visitor's perspective played out in the greatest of the three; that being Love.  - and that my friends is the essence of the book.  While The Visitor may be viewed by the reader as a Love story, the reality is, The Visitor is really a story about Love.