In my Father's house are many mansions: if it were not so, I would have told you. I go to prepare a place for you.
Read Chapter 14
Cyril of Alexandria
AD 444
Having forcibly enjoined upon them that they ought not to be troubled, and having bidden them rather believe both in God the Father and in Himself, He now tells them plainly as an encouragement to them to shake off their feebleness of mind, that they shall not be excluded from the holy courts, but shall be made to dwell in the mansions above, living their eternal life in the Church of the Firstborn, in the enjoyment of bliss unending. He says moreover that in His Father's house are many mansions, teaching them thereby that heaven is wide enough for all, and that the world He has created needs no enlargement at all to make it capable of containing those who love Him. And it seems likely that in speaking of the many mansions He wishes also to indicate the different grades of honour, implying that each one who desires to live a life of virtue will receive as it were his own peculiar place, and the glory that is suitable to his own individual acts. Therefore if the mansions in God the Fath...
In my Father's house. He does not say of your Father: for though God be the Father of all by creation, and of the just, by the grace of adoption; yet Christ in several places, calls him his Father, in a quite different sense, that is, as he was his eternal Father, as the ancient interpreters observe. (Witham)
These many mansions signify different degrees of glory in heaven. (St. Jerome, lib. ii. adv. Jovin.)
As He comforts Peter when bewildered by saying, but you shall follow afterwards, so also He gives this glimpse of hope to the others. For lest they should think that the promise was given to him alone, He says, In My Father's house are many mansions.
If it were not so I would have said to you, I go to prepare a place for you.
That is, The same place which receives Peter shall receive you. For a great abundance of dwellings is there, and it may not be said that they need preparation. When He said, You cannot follow Me now, that they might not deem that they were finally cut off, He added,
But that there is this distinction between the habitation of those who produce an hundred-fold, and that of those who produce sixty-fold, and that of those who produce thirty-fold; for the first will be taken up into the heavens, the second class will dwell in Paradise, and the last will inhabit the city; and that on this account the Lord said, "In my Father's house are many mansions: "
He wished elegantly to use the same term in his comparison of the ultimate reward; promising to the very house, which undergoes dissolution through suffering, a better house through the resurrection. Just as the Lore also promises us many mansions as of a house in His Father's home.
Albeit there be "many mansions", in the house of the same Father.