And I remember on one occasion, at a disputation held with certain Jews who were reputed learned men, having employed the following argument in the presence of many judges: “Tell me, sirs,” I said, “since there are two individuals who have visited the human race, regarding whom are related marvellous works surpassing human power— Moses, viz., your own legislator, who wrote about himself, and Jesus our teacher, who has left no writings regarding Himself, but to whom testimony is borne by the disciples in the Gospels— what are the grounds for deciding that Moses is to be believed as speaking the truth, although the Egyptians slander him as a sorcerer, and as appearing to have wrought his mighty works by jugglery, while Jesus is not to be believed because you are His accusers?
And yet there are nations which bear testimony in favour of both: the Jews to Moses; and the Christians, who do not deny the prophetic mission of Moses, but proving from that very source the truth of the statement regarding Jesus, accept as true the miraculous circumstances related of Him by His disciples. Now, if you ask us for the reasons of our faith in Jesus, give yours first for believing in Moses, who lived before Him, and then we shall give you ours for accepting the latter.
But if you draw back, and shirk a demonstration, then we, following your own example, decline for the present to offer any demonstration likewise. Nevertheless, admit that you have no proof to offer for Moses, and then listen to our defence of Jesus derived from the law and the prophets. And now observe what is almost incredible! It is shown from the declarations concerning Jesus, contained in the law and the prophets, that both Moses and the prophets were truly prophets of God.”
Source: Against Celsus (New Advent)