In Evelyn Waugh's The Ordeal of Gilbert Pinfold, what is Pinfold's relationship with religion?

The Ordeal of Gilbert Pinfold is arguably the least overtly religious of Evelyn Waugh's works. The elements of religion which do appear in the novel trend toward a factual and heavily autobiographical account of Waugh's own beliefs. Pinfold is a Roman Catholic. More specifically, he is a Roman Catholic convert, someone who converted to the religion in his adulthood. There is nothing sudden about this conversion; it is merely a calm, gradual assent to the teachings of the Church. For this, Pinfold earns the scorn and ridicule of a number of his friends and acquaintances, who cannot understand why someone they know and respect should subscribe to what they consider superstitious nonsense.
 
Pinfold himself is not entirely sure in his own tortured mind as to why he turned to Rome. The voices in his head taunt him about the sincerity of his religious beliefs. They goad him on, telling him that he is not really Catholic; in fact, he is actually Jewish and his real name is not Pinfold, but Peinfeld.
 
In the depths of his subconscious, then, Pinfold appears to be tormented by the nagging sense that his conversion to Catholicism was not motivated by the best of intentions. Certainly, Pinfold can hardly be described as particularly fervent in his faith, as the following line indicates:

The tiny kindling of charity which came to him through his religion sufficed only to temper his disgust and change it to boredom.

One is left with the distinct impression that Catholicism acts upon Pinfold in much the same way as the various stimulants he has been taking to ward off boredom. When the hallucinations start, it is not too surprising that Pinfold's inner doubts about the truth of his commitment to Catholicism rise to the surface to haunt him.
 
We might join with Pinfold's demonic chorus of subconscious voices in questioning the veracity and depth of his religious convictions. Pinfold describes himself as a "Catholic gentleman." There is just the slightest suggestion here that Pinfold's conversion to Catholicism has a certain snob appeal to it, along with all the other trappings of his rural existence—the country house, the coat of arms, and the retinue of servants. Perhaps Pinfold sees being a Catholic as connecting him to a vanished world before the time of the Reformation and the recusancy laws, when a handful of noble Catholic families kept the old faith alive: they were able to afford the punitive fines handed out for not attending Anglican services. In other words, what was previously stated explicitly in Brideshead Revisited is suggested implicitly in The Ordeal of Gilbert Pinfold.