The Eyes of the Master

As the Bible is the book of preference for me, I began to wonder what brought the people in the Scriptures to the place where they met the Master. The stories mostly wrote themselves. The hardest person to write about was the demonic from Gadarene. How does a person become so demon-possessed? Why does Jesus say to some, stop sinning? What did they do? They were more than likely doing the same things we are doing today.