The priests of Agon saw in wizardry what the priests of all the cults of the gods saw: a body of men and women who did not need to petition the deiti… - Barbara Hambly

Now they had given their wills to Agon, and it was Agon who acted through them—they could spy upon their benefactors, they could betray their friends, they could torture the weak, prostitute themselves, beat a helpless old cripple to death in an alleyway, and remain, in their hearts, good people, kindly people, men and women worthy of regard, because it was, after all, the Veiled God who was acting, not them.

Loving and hating were so close, two sides of a coin whose name was Need.

But too many people had come to him and Jaldis over the years, asking for magic to fix their lives. He knew of no spell which could not be twisted out of its purpose by fate, no potion which would for better or for worse change a human soul’s inner essence. No sigil he’d made had ever altered the words that rose automatically to a person’s lips when they weren’t thinking.
Yet people kept acting as if someday the laws of magic would spontaneously change and spells would do all these things.