The Five Books Against Marcion by Tertullian
Chapter II.--Why Christ's Coming Should Be Previously Announced.
Coming then at once to the point, I have to encounter the question, Whether Christ ought to have come so suddenly? (I answer, No.) First, because He was the Son of God His Father. For this was a point of order, that the Father should announce the Son before the Son should the Father, and that the Father should testify of the Son before the Son should testify of the Father. Secondly, because, in addition to the title of Son, He was the Sent. The authority, therefore, of the Sender must needs have first appeared in a testimony of the Sent; because none who comes in the authority of another does himself set it forth for himself on his own assertion, but rather looks out for protection from it, for first comes the support of him who gives him his authority. Now (Christ) will neither be acknowledged as Son if the Father never named Him, nor be believed in as the Sent One if no Sender gave Him a commission: the Father, if any, purposely naming Him; and the Sender, if any, purposely commissioning Him. Everything will be open to suspicion which transgresses a rule. Now the primary order of all things will not allow that the Father should come after the Son in recognition, or the Sender after the Sent, or God after Christ. Nothing can take precedence of its own original in being acknowledged, nor in like manner can it in its ordering. Suddenly a Son, suddenly Sent, and suddenly Christ! On the contrary, I should suppose that from God nothing comes suddenly, because there is nothing which is not ordered and arranged by God. And if ordered, why not also foretold, that it may be proved to have been ordered by the prediction, and by the ordering to be divine? And indeed so great a work, which (we may be sure) required preparation, as being for the salvation of man, could not have been on that very account a sudden thing, because it was through faith that it was to be of avail. Inasmuch, then, as it had to be believed in order to be of use, so far did it require, for the securing of this faith, a preparation built upon the foundations of pro-arrangement and fore-announcement. Faith, when informed by such a process, might justly be required of man by God, and by man be reposed in God; it being a duty, after that knowledge has made it a possibility, to believe those things which a man had learned indeed to believe from the fore-announcement.