CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 826–829

826 Charity is the soul of the holiness to which all are called: it "governs, shapes, and perfects all the means of sanctification."

If the Church was a body composed of different members, it couldn't lack the noblest of all; it must have a Heart, and a Heart BURNING WITH LOVE. And I realized that this love alone was the true motive force which enabled the other members of the Church to act; if it ceased to function, the Apostles would forget to preach the gospel, the Martyrs would refuse to shed their blood. LOVE, IN FACT, IS THE VOCATION WHICH INCLUDES ALL OTHERS; IT'S A UNIVERSE OF ITS OWN, COMPRISING ALL TIME AND SPACE - IT'S ETERNAL!

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." All members of the Church, including her ministers, must acknowledge that they are sinners. In everyone, the weeds of sin will still be mixed with the good wheat of the Gospel until the end of time. 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.

828 By canonizing some of the faithful, i.e., by solemnly proclaiming that they practiced heroic virtue and lived in fidelity to God's grace, the Church recognizes the power of the Spirit of holiness within her and sustains the hope of believers by proposing the saints to them as models and intercessors. "The saints have always been the source and origin of renewal in the most difficult moments in the Church's history." Indeed, "holiness is the hidden source and infallible measure of her apostolic activity and missionary zeal."
829 "But while in the most Blessed Virgin the Church has already reached that perfection whereby she exists without spot or wrinkle, the faithful still strive to conquer sin and increase in holiness. And so they turn their eyes to Mary": in her, the Church is already the "all-holy."