Tertullian, Against Marcion 3.3

‘There was no need,’ you say, ‘of such an order, because at once by the things themselves he would prove himself both Son and sent and God’s Christ through documents of powers.’ But I will deny that this species alone suited him for testimony—which he himself later also cashiered.

For when he announces many will come and do signs and put forth great powers even to the aversion of the elect, yet not for that to be admitted, he shows faith in signs and powers as rash—as easiest even among false Christs. Or what sort of thing is it if he wanted himself proved and known and received from powers—from where he did not want the others, themselves about to come as suddenly and as unpreached by any author?

If because he came before them and first sealed documents of powers, therefore, as if seizing a place at the baths, he occupied faith and snatched it from all later—see that he himself not be caught in the condition of the later, found later than the Creator, already known before and likewise working powers before and not otherwise foretelling that others after him must not be believed. Therefore if coming first and pronouncing first about later ones closes faith this way, he himself will already be prejudged by him than whom he is recognized later—and only the Creator’s authority will be for establishing this against later ones, who being later than none could not fail.

Already now, when I am about to prove the Creator formerly put forth through his servants the same powers you claim alone for faith in your Christ, and destined them to be put forth through his Christ, I can also from this rightly prescribe that your Christ all the more was not to be believed from powers alone, insofar as they could have been interpreted as of none other than the Creator—answering the Creator’s powers both done through servants and promised unto his Christ.

Though even if other—new—documents were found in your Christ, we would more easily believe even new things belong to him whose also the old are, than to him of only new things needing experiments of a faith that conquers antiquity—so that thus too he ought to have come preached, building faith by proper preachings as also by powers; especially about to come against the Creator’s Christ fortified by both signs and his own prophecies, that as rival of Christ he might shine through every species of diversities. But how would his Christ be preached from a god never preached? This then is what you demand: that neither your god nor your Christ be believed, because God ought not to be unknown and Christ ought to be known through God.