CCC 655 Finally, Christ’s Resurrection – and the risen Christ himself is the principle and source of our future resurrection: “Christ has been raised from the dead, the first fruits of those who have fallen asleep. .. For as in Adam all die, so also in Christ shall all be made alive.”1 The risen Christ lives in the hearts of his faithful while they await that fulfillment. In Christ, Christians “have tasted. .. the powers of the age to come”2 and their lives are swept up by Christ into the heart of divine life, so that they may “live no longer for themselves but for him who for their sake died and was raised.”3

CCC 1002 Christ will raise us up “on the last day”; but it is also true that, in a certain way, we have already risen with Christ. For, by virtue of the Holy Spirit, Christian life is already now on earth a participation in the death and Resurrection of Christ:
And you were buried with him in Baptism, in which you were also raised with him through faith in the working of God, who raised him from the dead. .. If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God.4

CCC 1003 United with Christ by Baptism, believers already truly participate in the heavenly life of the risen Christ, but this life remains “hidden with Christ in God.”5 The Father has already “raised us up with him, and made us sit with him in the heavenly places in Christ Jesus.”6 Nourished with his body in the Eucharist, we already belong to the Body of Christ. When we rise on the last day we “also will appear with him in glory.”7

CCC 1420 Through the sacraments of Christian initiation, man receives the new life of Christ. Now we carry this life “in earthen vessels,” and it remains “hidden with Christ in God.”8 We are still in our “earthly tent,” subject to suffering, illness, and death.9 This new life as a child of God can be weakened and even lost by sin.

CCC 2772 From this unshakeable faith springs forth the hope that sustains each of the seven petitions, which express the groanings of the present age, this time of patience and expectation during which “it does not yet appear what we shall be.”10 The Eucharist and the Lord’s Prayer look eagerly for the Lord’s return, “until he comes.”11

CCC 2796 When the Church prays “our Father who art in heaven,” she is professing that we are the People of God, already seated “with him in the heavenly places in Christ Jesus” and “hidden with Christ in God;”12 yet at the same time, “here indeed we groan, and long to put on our heavenly dwelling.”13
[Christians] are in the flesh, but do not live according to the flesh. They spend their lives on earth, but are citizens of heaven.14

1 I Cor 15:20-22.
2 Heb 6:5.
3 2 Cor 5:15; cf. Col 3:1-3.
4 Col 2:12; 3:1.
5 Col 3:3; cf. Phil 3:20.
6 Eph 2:6.
7 Col 3:4.
8 2 Cor 4:7; Col 3:3.
9 2 Cor 5:1.
10 1 Jn 3:2; Cf. Col 3:4.
11 1 Cor 11:26.
12 Eph 2:6; Col 3:3.
13 2 Cor 5:2; cf. Phil 3:20; Heb 13:14.
14 Ad Diognetum 5: PG 2, 1173.