Then, if any of you think we render superstitious adoration to the cross, in that adoration he is sharer with us. If you offer homage to a piece of wood at all, it matters little what it is like when the substance is the same: it is of no consequence the form, if you have the very body of the god. And yet how far does the Athenian Pallas differ from the stock of the cross, or the Pharian Ceres as she is put up uncarved to sale, a mere rough stake and piece of shapeless wood? Every stake fixed in an upright position is a portion of the cross; we render our adoration, if you will have it so, to a god entire and complete.
Tertullian
Apology
Chapter XVI