In Coelho's The Alchemist, Santiago is a non-believer as opposed to a follower of Christianity. Santiago is rooted in the rational world. Once a dreamer, he has been told by his father that success will not be found in a world of dreams. (This is echoed in the words of the crystal merchant as well.) Santiago takes the world as it is, unable to see that there might be more than what meets the eye. For Santiago, what you see is what you get. In being robbed by the young man he meets, and meeting the King of Salem, Melchizedek, Santiago's view of life is changed. The thief forces him to rethink his life. The king suggests that there is more to life than work. There are amazing things to be seen in common day occurrences (signs or omens) that can lead one to realize his Personal Legend:
There is one great truth on this planet: whoever you are, or whatever it is that you do, when you really want something, it’s because that desire originated in the soul of the universe. It’s your mission on earth.
This sense of celestial purpose is rooted in Christianity, for to achieve happiness and a sense of purpose, one needs to believe in "the soul of the universe"—in other words, God and His son, Jesus Christ. The search and observance of omens is much like being led by the Holy Spirit, another aspect of Christianity.
As Santiago continues his journey, he learns to depend less on what he thinks he knows:
Trust in the LORD with all your heart and lean not on your own understanding. Proverbs 3:5
Instead, he looks toward powers in nature: the wind, the sun, etc., all of which are part of the soul of the universe—and subservient to its greater power (also similar to God). Whereas Santiago has depended upon his sheep to survive, ultimately he sells them and walks away, ready to take a chance at success by relying on what he does not know with certainty, rather than depending on dependable employment. This is much like the call to a believer. Note the scripture Matthew 19:27:
Peter answered him, "We have left everything to follow you!" (NIV)
Santiago chooses to leave not only his livelihood (as did Christ's followers), but to proceed on faith. He goes in search of the alchemist of whom he knows nothing; Santiago is prepared to abandon everything in order to realize the promise of fulfillment, which is also a Christian doctrine—to walk away from the things of the world to follow Christ, and one's needs shall be met.
[Santiago] has to understand that the worst thing in life is to deny one’s dreams.
For a Christian, the worst thing in life is not failure in relationships or employment—or even death: it is failure to have a relationship with God, and a belief in the resurrection of His Son.
There are many Biblical allusions in the story:
Santiago is a shepherd; Jesus is often described as a shepherd tending his flock. Santiago recognizes the importance of Jesus’s words, “wherever your heart is, there your treasure lies also.”
It can be no surprise that Christian themes and images are abundant in The Alchemist. In 1986, Coelho went on a religious (Christian) pilgrimage of over 500 miles in Spain; during this time he had a “spiritual awakening.” This experience surfaces in the religious overtones in this book.
While Santiago starts out as a non-believer, eventually his life is changed: he lives by faith and realizes great happiness—a Christian belief.