Tertullian, Against Marcion 16

If Marcion stole the name Christ like a pickpocket lifting a purse, why did he also insist on being called Jesus—a name the Jews never expected? Even though we, by God's grace, have grasped the mystery of his sacraments and recognize that this name, too, was destined for Christ, that does not mean the Jews will recognize it; wisdom has been taken from them. To this day they wait for a Christ, not a Jesus, and they read Elijah as the Christ rather than Jesus. So who came in a name where Christ was not presumed? He could have come in the one name that was presumed. Instead he mixed the hoped-for and the unhoped-for, and both strategies collapse. If he claims to be Christ so he can meanwhile track down the Creator, the name Jesus contradicts him, because Jesus was never expected in the Creator's Christ. If he claims to be Jesus so he can belong to another god, the name Christ refuses him, because Christ was never hoped for as another's except the Creator's. I cannot say which of these alternatives holds up. But both will hold up in the Christ of the Creator, in whom Jesus is also found. "How?" you ask. Learn it even from the sharers in your error, the Jews. When Joshua son of Nun was appointed to succeed Moses, he was stripped of his old name and began to be called Jesus. "Granted," you say. We said earlier this was a figure of what was to come. Since Jesus Christ was to lead the people—that is us, born in the world's desert—into the promised land flowing with milk and honey, that is, into possession of eternal life, which is sweeter than anything—and this was to happen not through Moses, that is, not through the discipline of the Law, but through Jesus, that is, through the grace of the gospel, with us circumcised by the rock of Christ, for the rock is Christ (1 Cor 10:4)—therefore the man who was being prepared as a living image of this sacrament was also inaugurated with the figure of the Lord's name, surnamed Jesus. Christ himself testified that this name was his own even then, when he spoke to Moses. Who was speaking, if not the Spirit of the Creator, who is Christ? So when he commanded the people: "Behold, I send my angel before your face to guard you on the way and bring you into the land I have prepared for you; pay attention to him and obey his voice; do not rebel against him, for he will not pardon your transgression, for my name is in him" (Exod 23:20-21), he called him angel because of the magnitude of the virtues he would display and because of the prophet's office, announcing the divine will, but he called him Jesus because of the future sacrament of his name. For he confirmed the name he had imposed on him, since he had commanded that he be called not angel nor Joshua, but Jesus. Therefore, if both names belong to the Christ of the Creator, then neither name belongs to a Christ who is not of the Creator, just like the rest of the arrangement. Finally, a fixed and just boundary must be drawn between us from now on, determining that nothing whatsoever should be common to the Christ of another god and the Christ of the Creator. For we must defend the distinction just as we must repel the confusion, because you cannot prove that the Christ of another god came unless you demonstrate him to be utterly different from the Christ of the Creator, nor can we vindicate the Christ of the Creator unless we show him to be exactly as the Creator constituted him. On the names we have already closed the case: I claim Christ for myself, I defend Jesus for myself.