CCC
999 How? Christ is raised with his own body: “See my hands and my feet, that it is I myself”;551 but he did not return to an earthly life. So, in him, “all of them will rise again with their own bodies which they now bear,” but Christ “will change our lowly body to be like his glorious body,” into a “spiritual body”:552
But someone will ask, “How are the dead raised? With what kind of body do they come?” You foolish man! What you sow does not come to life unless it dies. and what you sow is not the body which is to be, but a bare kernel …What is sown is perishable, what is raised is imperishable… the dead will be raised imperishable… For this perishable nature must put on the imperishable, and this mortal nature must put on immortality.553
1016 By death the soul is separated from the body, but in the resurrection God will give incorruptible life to our body, transformed by reunion with our soul. Just as Christ is risen and lives for ever, so all of us will rise at the last day.
1017 “We believe in the true resurrection of this flesh that we now possess” (Council of Lyons II: DS 854). We sow a corruptible body in the tomb, but he raises up an incorruptible body, a “spiritual body” (cf ⇒ 1 Cor 15:42-44).
St. Paul, in one of his letters, says that we do not know what we will become. What we believe is that this nature, that we know possess, will be made perfect, as it once was.