How does Jim Casey's behavior liken him (Make him similar) to Jesus Christ?

There are always the initials "JC" but beyond that Casey is a visionary and a rebel. Originally a preacher Casey is not happy with mainstream religion, he no longer feels "the calling". Instead Casey opposes the corrupt authorities in charge, just as Christ opposed the PHARISEES. Casey joins a union and becomes something of a sage with followers that seem more like apostles. Even Tom is convinced that Casey is "on to something" and looks for his meaning.

Casey basically gives his life for the betterment of others in the book. He inspires a new way of thinking, a sense of fairness and brotherhood rather than greed and division. That's pretty Christ-figure-like!