The Christian Creed – the profession of our faith in God, the Father, the Son, and the Holy Spirit, and in God’s creative, saving, and sanctifying action – culminates in the proclamation of the resurrection of the dead on the last day and in life everlasting.
We firmly believe, and hence we hope that, just as Christ is truly risen from the dead and lives for ever, so after death the righteous will live for ever with the risen Christ and he will raise them up on the last day. Our resurrection, like his own, will be the work of the Most Holy Trinity:
If the Spirit of him who raised Jesus from the dead dwells in you, he who raised Christ Jesus from the dead will give life to your mortal bodies also through his Spirit who dwells in you.
The term “flesh” refers to man in his state of weakness and mortality. The “resurrection of the flesh” (the literal formulation of the Apostles’ Creed) means not only that the immortal soul will live on after death, but that even our “mortal body” will come to life again.
Belief in the resurrection of the dead has been an essential element of the Christian faith from its beginnings. “The confidence of Christians is the resurrection of the dead; believing this we live.”
How can some of you say that there is no resurrection of the dead? But if there is no resurrection of the dead, then Christ has not been raised; if Christ has not been raised, then our preaching is in vain and your faith is in vain…. But in fact Christ has been raised from the dead, the first fruits of those who have fallen asleep.
From the Catechism of the Catholic Church 988-991