"This is the sole Church of Christ, which in the Creed we profess to be one, holy, catholic and apostolic." These four characteristics, inseparably linked with each other, indicate essential features of the Church and her mission. The Church does not possess them of herself; it is Christ who, through the Holy Spirit, makes his Church one, holy, catholic, and apostolic, and it is he who calls her to realize each of these qualities.
Source: Catechism of the Catholic Church (Vatican.va)