Roger Zelazny

He played tune after forbidden tune, and the professional musicians put professional expressions of scorn upon their faces; but beneath the table several feet were tapping in slow time with the music.

The old religion is not only the religion - it is the revealed, enforced and frighteningly demonstrable religion. But don't think that last part too loudly.

"For a spur of the moment thing, you came up with a fairly engaging sermon."

"Thanks."

"Do you really believe what you preached?"

Sam laughed. "I'm very gullible when it comes to my own words. I believe everything I say, though I know I'm a liar."

Some quicksand is quicker than other quicksand. Fortunately, you are settling into that of the slower sort. [...] In the meantime, I suggest you solicit aid of my followers or learn the difficult art of mud-breathing.

There is a huge, burnished metal door, erected by the First, that is heavy as sin, three times the height of a man and half that distance in width. It is a full cubit thick and bears a head-sized ring of brass, a complicated pressure-plate lock and an inscription that reads, roughly, "Go away. This is not a place to be. If you do try to enter here, you will fail and also be cursed. If somehow you succeed, then do not complain that you entered unwarned, nor bother us with your deathbed prayers." Signed, "The Gods."