
One of the things I've never understood about a lot of brands of Christianity is their references to people as sheep. (I think they may use the same metaphor in other religions, but I don't remember off the top of my head.) Saying people are sheep isn't exactly a compliment. Sheep aren't among the top ten brightest mammals. Or even the top 100, probably. Mostly, they hang about and bleat and work on being fluffier and tastier. It's doesn't seem like a good way to convince people to join you. The shepherd analogy's not as bad, with the looking out for and caring for acts it implies, but there's problems there, too. Most herd animals aren't that bright, and most of the time they're just being raised to be eaten, with other benefits they provide along the way. Which would work fine for, say, Cthulhu, but again doesn't seem like a very good way to convince people God is infinite and loving and caring for them.
I can see uses to the comparisons, if you can make people buy them. Especially for priests or kinds who're "ordained by God." "Just stay home and don't think about it and let us take care of things like good little sheep. Now hold still, this won't hurt a bit. I need a nice wool jacket to protect you, after all." But that doesn't really leave much in it for the sheep, who'd be better off forming a co-op where they could get better prices for their wool and probably build some kind of better sheep-shaver that's more comfortable for the sheep, since they are sheep. And I think I've taken that metaphor far enough to break.
This leads to a larger point that I don't really have time to get into (because I've spent too long grazing and looking fluffy today), about how it's hard to convince people, even if you're right, if what you're saying attacks part of their self-image or things they value, which I'll save for another time. And yes, I know Terry Pratchett did the Sheep/Goats thing much better and more concisely in Small Gods, but if I didn't talk about things just because Terry Pratchett has already said them better, I'd have nothing to say.