Exodus 4:12

As touching the propriety of His names, it has already been seen that both of them are suitable to Him who was the first both to announce His Christ to mankind, and to give Him the further name of Jesus . The impudence, therefore, of Marcion’s Christ will be evident, when he says that many will come in his name, whereas this name does not at all belong to him , since he is not the Christ and Jesus of the Creator, to whom these names do properly appertain; and more especially when he prohibits those to be received whose very equal in imposture he is, inasmuch as he (equally with them) comes in a name which belongs to another, unless it was his business to warn off from a mendaciously assumed name the disciples (of One) who, by reason of His name being properly given to Him, possessed also the verity thereof. …

For as it is said, “It is man’s part to prepare his heart, and the answer of the tongue is from the Lord;” so also is it said, “Open thy mouth, and I will fill it.” For although, save by His assistance without whom we can do nothing, we cannot open our mouth, yet we open it by His aid and by our own agency, while the Lord fills it without our agency. For what is to prepare the heart and to open the mouth, but to prepare the will? And yet in the same scriptures is read, “The will is prepared by the Lord,” and, “Thou shalt open my lips, and my mouth shall show forth Thy praise.” So God admonishes us to prepare our will in what we read,” It is man’s part to prepare his heart;” and yet, that man may do this, God helps him, because the will is prepared by the Lord. …

And not from this circumstance only were these the greater, but also from their obedience: in that they shrink not, nor are they backward, like those of old;but, warned as they are of perils, and wars, and of those insupportable evils, they receive with great obedience His injunctions, as being heralds of a kingdom.

After that, because he had enjoined on them great things, to raise their courage, He says, “Lo! I am with you alway, even unto the end of the world.” Seest thou His own proper power again? Seest thou how those other things also were spoken for condescension? And not with those men only did He promise to be, but also with all that believe after them. For plainly the apostles were not to remain here unto “the end of the world;” but he speaks to the believers as to one body. For tell me not, saith He, of the difficulty of the things: for “I am with you,” who make all things easy. This He said to the prophets also in the Old Testament continually, as well to Jeremiah objecting his youth,as to Mosesand Ezekielshrinking from the office, “I am with you,” this here also to these men. …