CCC 333 From the Incarnation to the Ascension, the life of the Word incarnate is surrounded by the adoration and service of angels. When God “brings the firstborn into the world, he says: ‘Let all God’s angels worship him.’”1 Their song of praise at the birth of Christ has not ceased resounding in the Church’s praise: “Glory to God in the highest!”2 They protect Jesus in his infancy, serve him in the desert, strengthen him in his agony in the garden, when he could have been saved by them from the hands of his enemies as Israel had been.3 Again, it is the angels who “evangelize” by proclaiming the Good News of Christ’s Incarnation and Resurrection.4 They will be present at Christ’s return, which they will announce, to serve at his judgement.5

CCC 827 “Christ, ‘holy, innocent, and undefiled,’ knew nothing of sin, but came only to expiate the sins of the people. The Church, however, clasping sinners to her bosom, at once holy and always in need of purification, follows constantly the path of penance and renewal.”6 All members of the Church, including her ministers, must acknowledge that they are sinners.7 In everyone, the weeds of sin will still be mixed with the good wheat of the Gospel until the end of time.8 Hence the Church gathers sinners already caught up in Christ’s salvation but still on the way to holiness:
The Church is therefore holy, though having sinners in her midst, because she herself has no other life but the life of grace. If they live her life, her members are sanctified; if they move away from her life, they fall into sins and disorders that prevent the radiation of her sanctity. This is why she suffers and does penance for those offenses, of which she has the power to free her children through the blood of Christ and the gift of the Holy Spirit.9

CCC 1034 Jesus often speaks of “Gehenna” of “the unquenchable fire” reserved for those who to the end of their lives refuse to believe and be converted, where both soul and body can be lost.10 Jesus solemnly proclaims that he “will send his angels, and they will gather. .. all evil doers, and throw them into the furnace of fire,”11 and that he will pronounce the condemnation: “Depart from me, you cursed, into the eternal fire!”12

1 Heb 1:6.
2 Lk 2:14.
3 Cf. Mt 1:20; 2:13,19; 4:11; 26:53; Mk 1:13; Lk 22:43; 2 Macc 10:29-30; 11:8.
4 Cf. Lk 2:8-14; Mk 16:5-7.
5 Cf. Acts 1:10-11; Mt 13:41; 24:31; Lk 12:8-9. The angels in the life of the Church
6 LG 8 § 3; Cf. UR 3; 6; Heb 2:17; 726; 2 Cor 5:21.
7 Cf. 1 Jn 1:8-10.
8 Cf. Mt 13:24-30.
9 Paul VI, CPG § 19.
10 Cf. Mt 5:22, 29; 10:28; 13:42, 50; Mk 9:43-48.
11 Mt 13:41-42.
12 Mt 25:41.