4 For thus say those who are stubborn in folly:— Why did the Apostle say— Different is the body which is in heaven from that which is on earth? But he that hears this, let him hear also the other thing that the Apostle said:— There is an animal body, and there is a spiritual body. And again he said:— We shall all sleep, but we shall not all be changed. And again he said:— This that shall die must clothe itself with that that shall not die, and this which is corruptible must clothe itself with that which is incorruptible. Again he said:— We must all stand before the judgment-seat of Christ, that every man may be rewarded in his body for everything that before time was done by him, whether good or evil. Again he said:— What shall those do that are baptized for the dead?
For if the dead rise not, why are they baptized for them? Again he said:— If there is no resurrection of the dead, then is Christ not risen, and if Christ is not risen then your faith is vain, and our preaching. And if so we are found false witnesses in that we testified of God, that He raised up Christ, Whom He raised not up. Therefore, if the dead rise not, there is no judgment. And if there is no judgment, then let us eat and drink, for tomorrow we shall die.
Be not deceived; evil communications corrupt good purposes. Now as to this that the Apostle said:— The body that is in heaven is different from that which is on the earth, let this word be thus understood by you. When the body of the just shall arise and be changed, it is called heavenly. And that which is not changed is called earthly, according to its earthly nature.
Source: Demonstrations (New Advent)