The Church has frequently proclaimed her faith in the resurrection of the dead at the end of time. It forms, as it were, the "continuation" o f the Resurrection of Jesus Christ, the firstborn of many brethren (Rom 8:29), extended to all men and women, living and dead, just and sinners, that will take place when He comes at the end of time. At death the soul is separated from the body; with the resurrection, body and soul are reunited again for ever (Catechism of the Catholic Church, 997). The dogma of the resurrection of the dead refers to the fullness of immortality to which mankind is destined, but at the same time it is a vivid reminder of our dignity, and in particular of the dignity of the body. It speaks to us of the goodness of the world, of the body, of the value of a life lived out day by day, of the eternal vocation of matter. That is why in the second century when writing against the Gnostics, the phrase resurrection "of the flesh" was used—that is to say, human life in its most material aspect, temporal, changeable, apparently fleeting.
St Thomas Aquinas considered the doctrine of the resurrection to be natural in respect to its final cause (because the soul is made to be united to the body and vice versa), but supernatural in respect to its efficient cause (that is, God). [1]
The risen body will be real and material, but not earthly or mortal. St Paul rejected the idea of resurrection as a transformation happening within human history, and spoke of the resurrected body as "glorious" (cf. Phil 3:21) and "spiritual" (cf. Col 15:44). The resurrection of every man and woman, as happened with Christ, will take place after death.
The Church in the name of Christian faith does not promise us a successful life on this earth. She does not talk of a "utopia," since our earthly life will always be marked by the Cross. However, through the reception of Baptism and the Eucharist, the process of resurrection has is some way already begun (cf. CCC, 1000). According to St Thomas, at the resurrection the soul will inform the body so deeply that it will reflect the soul's moral and spiritual qualities. [2] Thus the final resurrection, which will take place when Christ comes in glory, will make possible the definitive judgement of the living and the dead.
With respect to the doctrine of the resurrection four points can be made:
—the doctrine of the final resurrection excludes theories of reincarnation, according to which the human soul after death migrates to another body, repeatedly if necessary, until it is finally purified. In this regard, Vatican Council II referred to "the one life we live," [3] for it is established that men die only once (Heb 9:27);
—the veneration of relics of the saints is a clear manifestation of the Church's faith in the resurrection of the body;
— although cremation of the human body is not illicit, unless it has been chosen for reasons that go against faith (cf. CCC, 1176), the Church strongly advises maintaining the pious custom of burying the dead. "The bodies of the dead must be treated with respect and charity, in the faith and hope of the resurrection. The burial of the dead is a corporal work of mercy: it honors the children of God, who are temples of the Holy Spirit." (CCC 2300);
— the resurrection of the dead accords with what Holy Scripture calls the coming of "the new heavens and the new earth" (cf. CCC, 1042; 2 Pet 3:13; Rev 21:1) Not only will mankind attain glory, but the entire cosmos in which we live and move will be transformed. "The Church to which all have been called in Christ Jesus and in which, by the grace of God, we achieve sanctity," we read in Lumen Gentium (no. 48), "will not achieve its full perfection until 'the time comes for the restoration of all things' (Acts 3:21), and when along with human kind the whole universe, so intimately united with man and through him achieving its end, will be perfectly renewed." There will certainly be continuity between this world and the new world, but also an important discontinuity. The hope of the definitive installation of Christ's kingdom shouldn't weaken but rather strengthen, with the theological virtue of hope, our effort to achieve progress on earth (CCC 1049).
https://opusdei.org/en/article/topic-16-i-believe-in-the-resurrection-of-the-body-and-life-everlasting/
Fr. Antonius David Tristianto, O.Carm.