Why is the pope considered the visible head of the Roman Catholic Church?

The pope is considered the visible head of the Roman Catholic Church based on the Petrine theory, which posits that Jesus Christ designated St. Peter the Apostle as his representative on Earth and the leader of the church.12

This belief is rooted in scriptural interpretations, particularly Matthew 16:18–19, where Jesus refers to Peter as the "rock" upon which he would build his church and grants him the "keys to the kingdom of heaven". Roman Catholic teaching holds that this authority was not limited to Peter but was passed down in perpetuity to his successors, the bishops of Rome.123

Consequently, the papacy is understood as a continuous line of apostolic succession. As the bearer of the Petrine office, the pope is recognized as the vicar of Christ and the supreme pontiff, possessing the authority to rule and govern the universal church. This status was formally defined by Vatican I, which affirmed that Christ established Peter as the visible head of the church with a primacy of true jurisdiction.23