In the Creed, after professing: “I believe in one Church”, we add the adjective “holy”; we affirm the sanctity of the Church, and this is a characteristic that has been present from the beginning in the consciousness of early Christians, who were simply called “the holy people” (cf. Acts 9,13, 32, 41; Rom 8,27; 1 Cor 6,1), because they were certain that it is the action of God, the Holy Spirit that sanctifies the Church.
But in what sense is the Church holy if we see that the historical Church, on her long journey through the centuries, has had so many difficulties, problems, dark moments? How can a Church consisting of human beings, of sinners, be holy? Sinful men, sinful women, sinful priests, sinful sisters, sinful bishops, sinful cardinals, a sinful pope? Everyone. How can such a Church be holy?
To respond to this question I would like to be led by a passage from the Letter of St Paul to the Christians of Ephesus. The Apostle, taking as an example family relationships, states that “Christ loved the Church and gave himself up for her, that he might sanctify her” (5,25-26). Christ loved the Church, by giving himself on the Cross. And this means that the Church is holy because she comes from God who is holy, he is faithful to her and does not abandon her to the power of death and of evil (cf. Mt 16,18). She is holy because Jesus Christ, the Holy One of God (cf. Mk 1,24), is indissolubly united to her (cf. Mt 28,20); She is holy because she is guided by the Holy Spirit who purifies, transforms, renews. She is not holy by her own merits, but because God makes her holy, it is the fruit of the Holy Spirit and of his gifts. It is not we who make her holy. It is God, the Holy Spirit, who in his love makes the Church holy.
– Pope Francis
General Audience of 02/10/2013