Metaphor

And more yet from Dorothy L. Sayers:

Moreover, whether we are dealing with simile or metaphor, it has to be remembered that every image is true and helpful only at its relevant point. God is, in a manner, light: but He is not a succession of wave-lengths in the prime matter. My love is like a red, red rose: but it is not advisable to mulch her with manure. The common sense of mankind can usually be trusted to disentangle the relevant from the irrelevant—but not always. The great dispute that was fought out at Nicaea turned upon the relevant point of a metaphor. That the Divine Son was begotten of the Divine Father was common ground; the Arians, a literal-minded set of people, argued that He must therefore be subsequent to Him, like a bodily procreation. The Orthodox, more sensitively aware of the trap concealed in metaphor, rejected the temptation to enclose God in space-time, holding stubbornly to the paradox of the Son's co-eternity. Indeed, nearly all heresies arise from the pressing of a metaphor beyond the point where the image ceases to be relevant.
from "The Poetry of Search and the Poetry of Statement" (1963) as reprinted in A Matter of Eternity.

"...[N]early all heresies arise from the pressing of a metaphor beyond the 

point where the image ceases to be relevant."

A Matter Of Eternity: Selections From The Writings of Dorothy L. Sayers