the real question is why I'm up at this hour...

Quotes from War in Heaven roughly in the order they appeared in the book not that it matters:

As a mere argument there's something lacking perhaps, in saying to a man who's lost his money and his house and his family and is sitting on the dustbin, all over boils, "Look at the hippopotamus."

"I will write," he thought, and took to a footpath, "the diary of a man who always got out at the wrong time, beginning with a Caesarean operation."

My favorite:

"Why was this bloody world created?"
"As a sewer for the stars," a voice in front of him said. "Alternatively to know God and glorify Him forever."...
"Quite," Kenneth said. "The two answers are not, of course, necessarily alternative. They might be con-con- consanguineous? contemporaneous? consubstantial? What is the word I want?
"Contemptible, concomitant, conditional, consequential, congruous, connectible, concupiscent, contaminable, considerable," the stranger offered him. "The last is, I admit, weak."
"The question was considerable," Kenneth answered. "You no doubt are considering it? You are even writing the answer down?"
"A commentary upon it," the other said. "But consanguinous was the word I wanted, or its brother." He wrote.

"But a man must fulfil his destiny even to minority. Shall I 'think the complete universe must be Subject to such a rag of it as me?'"

"But only because he's part of an institution," the Archdeacon said, "and one can more easily believe that institutions are supernatural than that individuals are. And an institution can believe in itself and wait, whereas an individual can't. Batesby can't afford to wait; he might die."

The best summary of the book:

So through the English roads the Graal was borne away in the care of a Duke, an Archdeacon, and a publisher's clerk, pursued by a country householder, the Chief Constable of a county, and a perplexed policeman. And these things also perhaps the angels desired to look into.
At least the Duke of North Ridings did. After a few moments he said to Mornington, "I suppose you know what we're doing?"
"We're carrying the Sans Graal," Mornington said. "Lancelot and Pelleas and Pellinore - no, that's not right - Bors and Percivale and Galahad. The Archdeacon's Galahad and you can be Percivale: you're not married, are you? And I'm Bors - but I'm not married either, and Bors was. It doesn't matter; you must be Percivale because you're a poet. And Bors was an ordinary workaday fellow like me. On, on to Sarras!"

*grins* yeah, I went quote happy somewhere between pages 94 and 120.