Dominica in Albis: How was it that the Body of the Risen Lord was a real Body, if It was able to pass through closed doors into the assembly of His disciples?

From the Holy Gospel according to John
John 20:19-31
In that time: Now when it was late that same day, the first of the week, and the doors were shut, where the disciples were gathered together, for fear of the Jews, Jesus came and stood in the midst, and said to them: Peace be to you. And so on

Homily by Pope St Gregory the Great.
26th on the Gospels.
When we hear this passage of the Gospel read, a question straightway knocketh at the door of our mind. How was it that the Body of the Risen Lord was a real Body, if It was able to pass through closed doors into the assembly of His disciples? But we ought to know that the works of God are no more wonderful when they can be understood by man's reason, and faith has lost her worth when her subject-matter is the subject-matter of human demonstration. Nevertheless, those very works of our Redeemer which are in themselves impossible to be understood, must be thought over in connection with other of His works, that we may be led to believe in things wonderful, by mean of things more wonderful still. That Body of the Lord, Which came into the assembly of the disciples through closed doors, was the Same, Which at Its birth, had become manifest to the eyes of men by passing out of the cloister of- the Virgin's womb without breaking the seal thereof. What wonder is it if that Body Which had come out of the Virgin's womb, without opening the matrix, albeit It was then on Its way to die, now that It was risen again from the dead and instinct for ever with undying life, what wonder is it, I say, if that Body passed through closed doors?
But Thou Lord