The Creed describes the Church as “One, Holy, Catholic and Apostolic.” She is One because she has one founder, God. She is also one because her members are united in one faith, sharing the same sacraments under one head, Christ, and the Pope, his vicar on earth. She is Holy because she is founded by God, and because her members are the baptised.
Through her ministry sinners receive Christ’s forgiveness and become holy. She is Catholic, which means ‘universal’, because she is for all races and nations in all ages. All salvation comes through her. She is Apostolic because her faith and practices have come to her from the apostles. Her leaders, the bishops, are successors of the apostles. She is also apostolic in that she is ‘sent out’ to preach the Gospel to all creation.
To live as a Christian in the full and proper sense means being a member of the Church. After all, Christ himself taught that he would build one Church – his Church – ‘on the rock of Peter’ (Mt 16:18), and that a Christian should ‘listen to the Church’ (Mt 18:17). In other words, Christ did not intend his followers to be isolated individuals or members of a patchwork of disunited communities. In addition, the New Testament strongly emphasises the centrality of the Church to the Christian life. St Paul claims that the Church is the ‘body of Christ’ (Eph 5:23), even describing their union like that of a husband and wife. This love between Christ and his Church is so strong that Christ regards persecution of his Church as persecution of himself (Acts 9:4; 22:7; 26:14). St Paul also describes the exclusion of an unrepentant sinner from the Church community as being ‘handed over to Satan’ (1 Tim 1:20; 1 Cor 5:5), implying that separation from the Church puts one’s soul at risk. Christian saints in later centuries also emphasised the importance of the Church. St Cyprian, a bishop and martyr in the third century, wrote, “He cannot have God for his father, who has not the Church for his mother” (Treatise on Unity, 6). So while one can be Christian without being in full communion with the Church, such a state is unsatisfactory. This condition of being separated from the Church is only sinful, however, when one is cut off from the Church due to one’s own fault.
The principal visible elements of this structure are the bishop of Rome (the Pope), all the bishops of the world in communion with him, their priests and deacons, those in religious and consecrated life and the lay faithful. Baptism is the means of entry into the Catholic Church, but not all the baptised are fully united with her. There are many Christians who are not Catholic, such as Protestant and Orthodox Christians. The Catholic Church believes that her essential structures and teachings are divinely established but recognises all that is good and true in other Christian communions. She is committed to the prayer and work for Christian unity which is called ecumenism.