The story centers on a nameless “whiskey priest” who is being persecuted by a ruthless government in a Mexican state in the 1930s. The priest makes an interesting protagonist, and is the vehicle used by Greene to examine the nature of sin, repentance, faith and other deep issues.
If any of these issues interest you, I highly recommend The Power and the Glory. It’s great.
I’ll leave you with one quote I liked a bunch:
“It was for this world that Christ had died; the more evil you saw and heard about you, the greater glory lay around the death. It was too easy to die for what was good or beautiful, for home or children or a civilization—it needed a God to die for the half-hearted and the corrupt.”