E87 Q97 Why is the Church called “holy”?

The Church is holy because the Holy Spirit dwells in it and sanctifies its members, setting them apart to God in Christ and calling them to moral and spiritual holiness of life. (Exodus 19:3–6; Leviticus 19:1–2; 20:22–26; Psalm 15; John 17:17–19; Acts 26:16–18; 1 Corinthians 3:16–17; Colossians 3:12–15)

Download the catechism here

St. John Chrysostom on The Peace of God