"He and I were both Catholics, so we used to go to mass together. He used to spend such a time in the confessional, I used to wonder what he had to say, because he never did anything wrong; never quite; at least, he never got punished. Perhaps he was just being charming through the grille." (1.2.38)
Anthony has little or no understanding of Catholicism as Sebastian understands it and as Charles will come to understand it by the end of the novel.
Often, almost daily, since I had known Sebastian, some chance word in his conversation had reminded me that he was a Catholic, but I took it as a foible, like his Teddy-bear. We never discussed the matter until on the second Sunday at Brideshead, when Father Phipps had left us and we sat in the colonnade with the papers, he surprised me by saying: "Oh dear, it's very difficult being a Catholic." (1.4.50)
Sebastian struggles with Catholicism because he takes it so seriously. Charles, who finds the whole thing (at this point in his flashback) to be somewhat ridiculous, can’t understand this.
"I mean about Christmas and the star and the three kings and the ox and the ass."
"Oh yes, I believe that. It's a lovely idea."
"But you can't believe things because they're a lovely idea."
"But I do. That's how I believe." (1.4.63-66)
Sebastian is the ultimate aesthete – even his religious beliefs are based on beauty.
"Well," I said, "if you can believe all that and you don't want to be good, where's the difficulty about your religion?"
"If you can't see, you can't." (1.4.69-70)
At what point in the novel does Charles begin to see this?
"Cordelia has promised to pray for me," I said.
"She made a novena for her pig," said Sebastian.
"You know all this is very puzzling to me," I said.
"I think we're causing scandal," said Brideshead.
That night I began to realize how little I really knew of Sebastian, and to understand why he had always sought to keep me apart from the rest of his life. He was like a friend made on board ship, on the high seas; now we had come to his home port. (1.4.156-160)
Charles earlier commented that, when discussing his family, Sebastian would retreat into another world where Charles could not follow. It seems now that religion is largely responsible for this rift between the two young men.
"When people hate with all that energy, it is something in themselves they are hating. Alex is hating all the illusions of boyhood – innocence, God, hope. Poor Lady Marchmain has to bear all that." (1.4.236)
Here Cara is trying to explain why everyone hates Lady Marchmain. Cordelia later continues this discussion when she says that people hate Lady Marchmain as an indirect way of hating God.
Between her tears she talked herself into silence. I could do nothing; I was adrift in a strange sea; my hands on the metal-spun threads of her tunic were cold and stiff, my eyes dry; I was as far from her in spirit, as she clung to me in the darkness, as when years ago I had lit her cigarette on the way from the station; as far as when she was out of mind, in the dry, empty years at the Old Rectory and in the jungle. (2.3.119)
Just as religion was the barrier between Charles and Sebastian, so it is here between him and Julia – not because he resents her for her beliefs, but because he simply cannot understand them.
"There were four of you," I said. "Cara didn't know the first thing it was about, and may or may not have believed it; you knew a bit and didn't believe a word; Cordelia knew about as much and believed it madly; only poor Bridey knew and believed, and I thought he made a pretty poor show when it came to explaining. And people go round saying, 'At least Catholics know what they believe.' We had a fair cross-section to-night–"
"Oh, Charles, don't rant. I shall begin to think you're getting doubts yourself." (2.5.161-2)
Actually, Julia is right – Charles is beginning to doubt his own doubt. We know that he has found God by the end of the novel, so this is the first inkling of his eventual conversion.
"That is what it would mean; starting a life with you, without Him. […] But I saw to-day there was one thing unforgivable – like things in the schoolroom, so bad they are unpunishable, that only Mummy could deal with – the bad thing I was on the point of doing, that I'm not quite bad enough to do; to set up a rival good to God's. […] It may be a private bargain between me and God, that if I give up this one thing I want so much, however bad I am, He won't quite despair of me in the end." (2.5.247)
Is this really Julia’s reason for leaving Charles? Or is she justifying? Are the barriers she faces religious, or simply social taboos?