To put it simply, an idealist is one who imagines that the world can be a much better place than it is. What could be dangerous about that? The lieutenant, in many ways, illustrates the danger. Obsessed with the way things could be, he remains mired in dissatisfaction and bitterness about the way things actually are. Although the wish to help the poor is a noble sentiment, dreams of "starting over", erasing history, and wiping out all religious belief are simply not realizable. Moreover, being unable to bring about the impossible leads the lieutenant to feelings of frustration and anger, an even more keen awareness of how imperfect the world is, and hatred for those people whom he views as obstacles to the realization of his dream. Moreover, his conviction that he knows what is best for the people is itself a form of arrogance. The priest, on the other hand, comes to accept suffering and death as a part of life; that is not to say that he does not wish to help alleviate suffering, but his faith in the next world helps him to accept the trials and hardships of this one.
Greene is interested in showing the gap between life as it is remembered, recorded or retold, and life as it is lived. Acts of storytelling occur quite frequently throughout the novel. The most obvious example is the story of Juan, the young martyr. One thing that becomes apparent by the novel's close is how very different Juan's story of martyrdom is from the priest's. Juan's life is characterized from start to finish by composure, loyalty and, above all, unshakeable faith. Although the priest certainly is an admirable figure, especially by the time of the novel's close, he still faces death afraid and unable to repent. But Greene is not juxtaposing the two accounts of martyrdom merely to highlight the priest's shortcomings, but rather to show that real-life differs from idealistic stories, in most cases. This theme extends beyond storytelling to other forms of representation. For example, the priest takes note of how little the gringo looks like his picture on the wanted poster in the police office, and the lieutenant fails to recognize the priest because the priest does not have the delicate hands that a stereotypical priest would have. Stories, pictures and other kinds of representation can give a misleading, exaggerated picture of a person, and Greene is interested in writing about reality as it is truly experienced, even if he himself is attempting to create that sense of unvarnished reality through his own storytelling.
Love and hate, beauty and suffering, good and evil are just a few of the many pairs of seeming opposites that Greene insists are not really opposites at all. In the lieutenant's case, for example, his hatred of priests originally stems from a love of and a concern for poor people. Both feelings stem from the same strong emotions—the desire to protect the innocent and the rejection of injustice in any form. The priest often discovers the beauty of life in the moments of greatest suffering and hardship. Moreover, the priest and the lieutenant, who play such opposing roles throughout the novel (i.e. the hunted and hunter, the priest-hater and the priest) come together at the end of the novel and reach a kind of qualified understanding of one another.
One of the most knotty problems considered in this book is how difficult it is for a Christian to be truly humble. Humility is a quality that a Christian is supposed to strive to realize in his life; yet as soon that person thinks that he is succeeding in being humble, he can become proud of his success. The priest realizes that he is trapped in this quagmire, and that he originally stayed in Mexico during the persecution so that he would appear good before God and his people. Yet, in the novel, he never allows himself to remain complacent in the sacrifices he has made, or the Christian feelings he has. Despairing over his weakness and inability to be truly humble, the priest, paradoxically, attains true humility.
There are many references to animals throughout this novel. The most striking one, perhaps, is the crippled dog that the priest discovers at the abandoned estate. In that scene the priest battles the dog over a bone with a few bites of meat on it and the implicit question is whether anything separates us from the animals. Are human beings reducible to the will to survive? It is a question of great importance to the priest, who often is at a loss to justify his desire to live (especially when he considers the pain his presence inflicts upon others). His struggle with the maimed mongrel over a morsel of meat is a pathetic scene, one in which hunger and the will to live seem to win out over human dignity, and the priest recognizes this. There are also many mentions of insects throughout the novel, notably in scenes involving the lieutenant. Greene refers to insects hurling themselves into lamps or being crushed underfoot. Pointless life careening to pointless death seems to be the import of these details, and the implicit question is whether human life is similarly futile and meaningless.
A striking thing about this novel is the prevalence of "half-things": the mestizo is a "half-caste"; the priest despairs most often over the "half-hearted"; Padre Jose is half-priest, half-husband; Mr. Tench seems half-alive; there are dozens of examples throughout the novel. Moreover, we can see by this list alone that half-things more often than not play some detrimental role in this novel. The priest and the lieutenant are by and large, exceptions—people who refuse half-measures and instead tend towards extremes. Near the end of the novel, the mestizo exclaims to the priest, "you do nothing in moderation." Although the extremities are often dangerous—particularly in the case of the lieutenant's actions—Greene seems to suggest that it is better to live life with intensity and passionate commitment than it is to live in an indifferent or complacent fashion.
Many things are abandoned in this novel, and the words "abandoned" or "abandonment" crop up repeatedly. Many of the townspeople feel that the clergy has abandoned them, and the priest, in turn, feels that the people have abandoned him. Mr. Tench has abandoned his family, Captain Fellows and Mrs. Fellows abandon their house and their dog, and the priest tries to abandon the mestizo on the road to Carmen. These are just a few examples. It is an important motif, because it implicitly raises the most important question, whether human beings have been abandoned by God and left to the cruelty of nature and each other. Significantly, the greatest act of heroism in the novel—the priest's decision to return to help the gringo—is a refusal to abandon someone in need, and a refusal to abandon a dangerous and ugly world.
Alcohol recurs throughout this book as a symbol with two very different meanings. On the one hand, it represents weakness for "the whiskey priest"; a mark, to him, of his unworthiness and the decadence of his former life. The authorities' attempts to rid the state of alcohol are a manifestation of the impossible and detrimental desire to purge the world of all human weakness. On the other hand, alcohol is an integral part of the Catholic mass, evidenced by the priest's persistent attempts to procure wine. As we see throughout the book, the sacred and the profane are often portrayed not as opposites, but as two halves of the same coin.
At many points throughout the book, different characters seem to stand in for figures from the New Testament. Perhaps the most obvious example is the mestizo, whom the priest expressly refers to as "Judas." During his night in the hut with the mestizo, the priest has trouble keeping himself awake, recalling the night Jesus spends in the garden with the disciples who cannot seem to keep themselves awake. Of course, by the end of the novel, the priest's death is reminiscent of Christ's willing sacrifice and his execution at the hands of the authorities. Despite the similarities, one must pay close attention to the differences as well, since Greene is extremely careful to emphasize that his characters have the free will to decide their own paths in life, and are not merely playing out some predetermined scheme.
Coral Fellows, Brigida and the boy are just a few of the children who play key roles in this novel. In a land of violence and persecution, where a sense of community seems to have all but disappeared, the question of what will become of the next generation looms large. The lieutenant seems to be motivated by a desire to help children avoid the pitfalls of his own childhood by wiping out religion. He cannot completely eradicate the memory of religion from the minds of the older generation, but perhaps the work he and his fellow officers have done will effectively rid the next generation of all religious sentiment. The priest is consumed with worry over the fate of his daughter, Brigida, fearing that she has already been altered for the worse by the cruelty of the world. Thus, children seem to symbolize both a future that is very much hanging in the balance, and a present innocence that may be threatened, or even permanently damaged, by the conflicted times in which they live.