Question: "What was Unam Sanctum?"
Answer: Unam Sanctum (which means “Holy One” in Latin) was an edict issued by Pope Boniface VIII in 1302 that gave extreme authority to the papal office. In this Unam Sanctum document, called a papal bull, Pope Boniface declared the supremacy of the Pope, asserted the necessity for absolute obedience to papal decrees as a requirement for salvation, and called for unity within the Catholic Church. The Unam Sanctum stated emphatically that salvation apart from the Roman Catholic Church is not possible and that all life must submit to the spiritual head, which is the Pope. To resist papal authority is to be in defiance of God.
The setting in which this Unam Sanctum was birthed was the growing conflict between Pope Boniface VIII and King Philip of France. Philip, along with King Edward I of England, refused to allow the church as much political power as it demanded. The kings did not want the church interfering in legal and civic matters, and most of the Catholic clergy supported this stance. This infuriated Pope Boniface, especially when King Philip imprisoned a French bishop for treason. The Pope feared his power was diminishing, so, in response, he fired off the Unam Sanctum in an effort to regain his position.
The Unam Sanctum was considered too extreme, even by most of the clergy, and was soundly rejected by the kings. King Philip responded to Boniface’s attempt to bully him by accusing Boniface of heresy, blasphemy, and even sodomy and then sent his henchmen to capture the Pope. Boniface was soon rescued, but he died shortly after, a broken and defeated man.
Even so, the Unam Sanctum was incorporated into Catholic law and was one of the elements of Catholicism that compelled Martin Luther to cry out for reform in the early 1500s. The foundation upon which Unam Sanctum was created is the Catholic belief in apostolic succession—that the authority of the apostles has been handed down to each leader of the true church. Popes believe that they alone can speak for God; therefore, to resist their words is to resist God. However, nowhere in Scripture are we told that the apostles transferred their authority to others. Scripture is clear that apostles had certain qualifications: they had seen the resurrected Christ (1 Corinthians 9:1), were explicitly chosen by the Holy Spirit (Acts 9:15), and had the ability to perform signs and wonders (Acts 2:43; 2 Corinthians 12:12). No Pope has ever fit all three of those qualifications.
Unam Sanctum is yet another example of what happens when we depart from the written Word of God as our only authority. When we add to or take away from that which God has already stated, we quickly fall into error. Scripture teaches that no one can be saved through church membership, baptism, or the blessing given from another fallible human being. We are saved through faith in the death and resurrection of Jesus Christ who paid the debt we owe God for our rebellion against Him (Ephesians 2:8–9; Titus 3:5; John 3:16–18; Acts 16:31; John 14:6). The dying thief on the cross next to Jesus knew nothing of Unam Sanctum, yet he was saved because he trusted in Christ (Luke 23:41–43). Jesus will do the same for anyone—Catholic, Protestant, or atheist—who calls upon His name (Acts 2:21; Romans 10:9–10).