CCC 147 The Old Testament is rich in witnesses to this faith. The Letter to the Hebrews proclaims its eulogy of the exemplary faith of the ancestors who “received divine approval”.1 Yet “God had foreseen something better for us”: the grace of believing in his Son Jesus, “the pioneer and perfecter of our faith”.2

CCC 165 It is then we must turn to the witnesses of faith: to Abraham, who “in hope. .. believed against hope”;3 to the Virgin Mary, who, in “her pilgrimage of faith”, walked into the “night of faith”4 in sharing the darkness of her son’s suffering and death; and to so many others: “Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with perseverance the race that is set before us, looking to Jesus the pioneer and perfecter of our faith.”5

CCC 598 In her Magisterial teaching of the faith and in the witness of her saints, the Church has never forgotten that “sinners were the authors and the ministers of all the sufferings that the divine Redeemer endured.”6 Taking into account the fact that our sins affect Christ himself,7 the Church does not hesitate to impute to Christians the gravest responsibility for the torments inflicted upon Jesus, a responsibility with which they have all too often burdened the Jews alone:
We must regard as guilty all those who continue to relapse into their sins. Since our sins made the Lord Christ suffer the torment of the cross, those who plunge themselves into disorders and crimes crucify the Son of God anew in their hearts (for he is in them) and hold him up to contempt. And it can be seen that our crime in this case is greater in us than in the Jews. As for them, according to the witness of the Apostle, “None of the rulers of this age understood this; for if they had, they would not have crucified the Lord of glory.” We, however, profess to know him. And when we deny him by our deeds, we in some way seem to lay violent hands on him.8
Nor did demons crucify him; it is you who have crucified him and crucify him still, when you delight in your vices and sins.9

CCC 1161 All the signs in the liturgical celebrations are related to Christ: as are sacred images of the holy Mother of God and of the saints as well. They truly signify Christ, who is glorified in them. They make manifest the “cloud of witnesses”10 who continue to participate in the salvation of the world and to whom we are united, above all in sacramental celebrations. Through their icons, it is man “in the image of God,” finally transfigured “into his likeness,”11 who is revealed to our faith. So too are the angels, who also are recapitulated in Christ:
Following the divinely inspired teaching of our holy Fathers and the tradition of the Catholic Church (for we know that this tradition comes from the Holy Spirit who dwells in her) we rightly define with full certainty and correctness that, like the figure of the precious and life-giving cross, venerable and holy images of our Lord and God and Savior, Jesus Christ, our inviolate Lady, the holy Mother of God, and the venerated angels, all the saints and the just, whether painted or made of mosaic or another suitable material, are to be exhibited in the holy churches of God, on sacred vessels and vestments, walls and panels, in houses and on streets.12

CCC 2683 The witnesses who have preceded us into the kingdom,13 especially those whom the Church recognizes as saints, share in the living tradition of prayer by the example of their lives, the transmission of their writings, and their prayer today. They contemplate God, praise him and constantly care for those whom they have left on earth. When they entered into the joy of their Master, they were “put in charge of many things.”14 Their intercession is their most exalted service to God’s plan. We can and should ask them to intercede for us and for the whole world.

1 Heb 11:2, 39.
2 Heb 11:40; 12:2.
3 Rom 4:18.
4 LG 58; John Paul II, RMat 18.
5 Heb 12:1-2. Article 2.
6 Roman Catechism I, 5, 11; cf. Heb 12:3.
7 Cf. Mt 25:45; Acts 9:4-5.
8 Roman Catechism I, 5, 11; cf. Heb 6:6; 1 Cor 2:8.
9 St. Francis of Assisi, Admonitio 5, 3.
10 Heb 12:1.
11 Cf. Rom 8:29; 1 Jn 3:2.
12 Council of Nicaea II: DS 600.
13 Cf. Heb 12:1.
14 Cf. Mt 25:21.