The Church is marked by four signs which help to identify its true nature: one, holy, catholic, and apostolic. An understanding of these four signs will help form a definition of the Catholic Church.
The Church is One. The unity of the Church is rooted in the unity of the Holy Trinity – God the Father, God the Son, and God the Spirit. The Church has a common body of beliefs and is universal in doctrine. All united under the Pope, Catholics profess one faith, creed, and set of moral teachings.
The Church is Holy. God is the ultimate source of holiness in the Church and Jesus Christ is the model of holiness for the Church. The Church is holy since it was instituted by Christ, who gave the Church the gift of the Holy Spirit to continue his mission and ministry on earth. Through the Church, one is called to live a life which leads to the wholeness of personal development and true relationship with God, the source of life and eternal salvation.
The Church is Catholic. The word “Catholic” means “universal.” The Church, from the time Jesus commissioned the Apostles until the present age, has always been centered on spreading the message of Jesus Christ. The Church of yesterday, today, and tomorrow will always have Christ as our foundation. Furthermore, the Church is for all people throughout the world. The Mass and the other sacraments are celebrated throughout the world, bringing all Catholics together in a spirit of prayer and unity.
The Church is Apostolic. The Bishops, who are the successors to the Apostles, in union with the Pope, continue to teach, sanctify, and guide the church until Christ comes again. The doctrine and way of life of the Church is the same today as it was in the time of the Apostles. The good news of Jesus Christ announced by the Apostles almost 2,000 years ago continues to be announced by the Church today. Furthermore, the Church recognizes the apostolic mission – to reach out to people of all nations and preach the Good News of the Gospel.