4 If haply there be any heretics who still in their hearts maintain that Christ exhibited Himself to sight, but that Christ's was not very flesh; let them now lay aside that error, and let the Gospel persuade them. We do but blame them for entertaining this conceit: He will damn them if they shall persevere in it. Who are you who dost not believe that a body laid in the sepulchre could rise again? If you are a Manichee, who dost not believe that He was crucified either, because you do not believe that He was even born, you declare that all that He showed was false.
He showed what was false, and do you speak the truth? Thou dost not lie with your mouth, and did He lie in His body? Lo you suppose that He appeared unto the eyes of men what He really was not, that He was a spirit, not flesh. Hear Him: He loves you, let Him not condemn you. Hear Him speaking: lo, He speaks to you, you unhappy one, He speaks to you, “Why are you troubled, and why do thoughts ascend into your heart?” “See,” says He, “My hands and My feet. Handle and see, because a spirit has not flesh and bones as you see Me have.” This spoke the Truth, and did He deceive? It was a body then, it was flesh; that which had been buried, appeared. Let doubting perish, and meet praise ensue.
Source: Sermons on Selected Lessons of the New Testament (New Advent)