How we cite our quotes: (Chapter.Paragraph)
Quote #1
"That is a story invented by the Telmarines. Your Kings are in deadly fear of the sea because they can never quite forget that in all stories Aslan comes from over the sea." (4.73)
In Prince Caspian, Aslan represents Jesus Christ, and in the world of Narnia, there is no question that his religion is the true and righteous one. Don't agree? You'd definitely be reading against the grain.
Quote #2
"Do you believe all those old stories?" asked Trumpkin.
"I tell you, we don't change, we beasts," said Trufflehunter. "We don't forget. I believe in the High King Peter and the rest that reigned at Cair Paravel, as firmly as I believe in Aslan himself." (5.67-68)
Trumpkin is to Prince Caspian as Edmund was to The Lion. Both characters start as skeptics and eventually come to believe in Aslan. To be fair though, Trumpkin had it way easier than Edmund did (though Edmund himself might be partly to blame for that).
Quote #3
"And if I hadn't believed in [Aslan] before, I would now. Back there among the Humans the people who laughed at Aslan would have laughed at stories about Talking Beasts and Dwarfs. Sometimes I did wonder if there really was such a person as Aslan: but then sometimes I wondered if there were really people like you. Yet there you are." (5.70)
Caspian's faith grows by the sight of talking animals. As in real life, faith and religion go hand-in-hand in the novel. You can't have one without the other.
Quote #4
"I'll believe in anyone or anything," said Nikabrik, "that'll batter these cursed Telmarine barbarians to pieces or drive them out of Narnia. Anyone or anything, Aslan or the White Witch, do you understand?" (6.12)
Yeah… Nikabrik kind of misses the point here. He's so focused on the ends that he disregards the means, but in religion, the means generally justify the ends.
Quote #5
In the center was the Stone itself—a stone table, split right down the center, and covered with what had once been writing of some kind: but ages of wind and rain and snow had almost worn them away in old times when the Stone Table had stood on the hill top, and the Mound had not yet been built above it. (7.41)
Most—not all—religions use icons, relics, and artifacts in their worship. The Stone Table from The Lion returns to play just such a role in Prince Caspian, representing a holy place and haven for Caspian's holy war.
Quote #6
"And if Aslan himself comes, [Cair Paravel] would be the best place for meeting him too, for every story says that he is the son of the great Emperor-over-the-Sea, and over the sea he will pass." (7.51)
Quote #7
"But they won't believe me!" said Lucy.
"It doesn't matter," said Aslan. (10.65)
Faith returns. Lucy's faith is conflicted by her siblings' lack of faith—a key conflict for the theme of religion in the novel.
Quote #8
"And I have no use for magic lions which are talking lions and don't talk, and friendly lions though they don't do us any good, and whooping big lions though nobody can see them. It's all bilge and beanstalks as far as I can see." (11.8)
Trumpkin's skepticism neatly encapsulated in a handy quote. If he can't see it, he doesn't believe in it. When he meets Aslan later, he totally believes.
Quote #9
Down below that in the Great River, now at its coldest hour, the heads and shoulders of the nymphs, and the great weedy-bearded head of the river-god, rose from the water. (11.54)
Unlike most Christians, C.S. Lewis didn't demonize paganism or its gods. Instead, he believed these gods helped us broaden our understanding of Christianity. Lewis's thoughts on this matter are really interesting, and there are many places to read up on them. Here's one.
Quote #10
"We don't know when [Aslan] will act. In his time, no doubt, not ours. In the meantime he would like us to do what we can on our own." (13.1)
This passage does a nice job of summing up the novel's attitude on religion a la C.S. Lewis: have faith and act in the best way you can. Done and doner.