2 But what said the Lord Jesus? “Why are you troubled, and why do thoughts ascend into your hearts?” If thoughts ascend into your heart, the thoughts come from the earth. But it is good for a man, not that a thought should ascend into his heart, but that his heart should itself ascend upwards, where the Apostle would have believers place their hearts, to whom he said, “If you be risen with Christ, mind those things which are above, where Christ is sitting at the right hand of God.
Seek those things which are above, not the things which are upon the earth. For you are dead, and your life is hid with Christ in God. When Christ your life shall appear, then shall you also appear with Him in glory.” In what glory? The glory of the resurrection. In what glory? Hear the Apostle saying of this body, “It is sown in dishonour, it shall rise in glory.” This glory the Apostles were unwilling to assign to their Master, their Christ, their Lord: they did not believe that His Body could rise from the sepulchre: they thought Him to be a Spirit, though they saw His flesh, and they believed not their very eyes.
Yet we believe them who preach but do not show Him. Lo, they believed not Christ who showed Himself to them. Malignant wound! Let the remedies for these scars come forth. “Why are you troubled, and why do thoughts ascend into your hearts? See My hands and My feet,” where I was fixed with the nails. “Handle and see.” But ye see, and yet do not see. “Handle and see.” What? “That a spirit has not flesh and bones, as you see me have. When He had thus spoken,” so it is written, “He showed them His hands and His feet.”
Source: Sermons on Selected Lessons of the New Testament (New Advent)