9 Let the Church then say those last words also, “If you had believed Moses, you would believe me also; for he wrote of me;” for that I am His body of whom he wrote. And of the Church did Moses write. For I have quoted the words of Moses “In your seed shall all nations of the earth be blessed.” Moses wrote this in the first book. If you believed Moses, you would also believe Christ. Because ye despise Moses' words, it must needs be that you despise the words of Christ.
“They have” there, says He, “Moses and the Prophets, let them hear them. Nay, father Abraham, but if one went unto them from the dead,” him they will hear. “And He said, If they hear not Moses and the Prophets, neither will they believe, if one rise again from the dead.” This was said of the Jews: was it therefore not said of heretics? He had risen from the dead, who said, “It behooved Christ to suffer, and to rise again from the dead the third day.” This I believe. I believe it, he says.
Do you believe? Wherefore do you not believe what follows? In that you believe, “It behooved Christ to suffer, and to rise again from the dead the third day;” this was spoken of the Head; believe also that which follows concerning the Church, “That repentance and remission of sins should be preached throughout all nations.” Wherefore do you believe as touching the Head, and believest not as touching the Body? What has the Church done to you, that you would so to say behead her?
You would take away the Church's Head, and believe the Head, leave the Body as it were a lifeless trunk. It is all to no purpose that you caress the Head, like any devoted servant. He that would take off the head, does his best to kill both the head and the body. They are ashamed to deny Christ, yet are they not ashamed to deny Christ's words. Christ neither we nor you have seen with our eyes. The Jews saw, and slew Him. We have not seen Him, and believe; His words are with us.
Compare yourselves with the Jews: they despised Him hanging upon the Tree, you despise Him sitting in heaven; at their suggestion Christ's title was set up, by your setting yourselves up, Christ's Baptism is effaced. But what remains, Brethren, but that we pray even for the proud, that we pray even for the puffed up, who so extol themselves? Let us say to God on their behalf, “Let them know that the Lord is Your Name; and” not “that” men, but “Thou Only art the Most High over all the earth.” Let us turn to the Lord, etc.
Source: Sermons on Selected Lessons of the New Testament (New Advent)