The tragedy of Father Merrin is that his victory is inextricably linked to his death. In both the film and the book, Merrin dies before the exorcism is complete. In the film, his death—peaceful, having administered last rites to himself—suggests a surrender to a higher will. In Blatty's original conception, however, Merrin is a martyr of the spirit. He gives his life not to "win" in the conventional sense, but to clear the path for Karras. Merrin absorbs the brunt of the evil, serving as the lightning rod, so that Karras can make the ultimate sacrifice of self to save the child.
To understand Merrin, one must first understand his origin in the 1973 film’s prologue: the dig at Hatra, Iraq. This is not mere set dressing; it is the psychological genesis of the character. padre merrin