For how is He before all, if He is not before all things? How, again, is He before all things, if He is not "the first-born of every creature"-if He is not the Word of the Creator? Now how will he be proved to have been before all things, who appeared after all things? Who can tell whether he had a prior existence, when he has found no proof that he had any existence at all? In what way also could it have "pleased (the Father) that in Him should all fulness dwell? " For, to begin with, what fulness is that which is not comprised of the constituents which Marcion has removed from it,-even those that were "created in Christ, whether in heaven or on earth," whether angels or men? which is not made of the things that are visible and invisible? which consists not of thrones and dominions and principalities and powers? If, on the other hand, our false apostles and Judaizing gospellers have introduced all these things out of their own stores, and Martian has applied them to constitute the fulness of his own god, (this hypothesis, absurd though it be, alone would justify him; ) for how, on any other supposition, could the rival and the destroyer of the Creator have been willing that His fulness should dwell in his Christ? To whom, again, does He "reconcile all things by Himself, making peace by the blood of His cross," but to Him whom those very things had altogether offended, against whom they had rebelled by transgression, (but) to whom they had at last returned? Conciliated they might have been to a strange god; but reconciled they could not possibly have been to any other than their own God.
Source: Against Marcion Book V