How did the Church begin?

God planned the gathering of His faithful people together into a single community from the beginning of human history (Catechism of the Catholic Church 759). We see this plan played out over the various stages of humanity in Scripture. For example, God’s Old Testament covenant with Abraham leads eventually to the establishment of the kingdom of Israel, a precursor to the Church as it exists today. As God more fully reveals Himself to mankind, and human knowledge about God grows, the stage becomes set for God to fully reveal Himself in Christ, Who finally establishes a single community of believers, God’s one true Church.  

Jesus prepares His Church by appointing twelve apostles. The Catechism (CCC) explains: “Representing the twelve tribes of Israel, they are the foundation stones of the new Jerusalem. The Twelve and the other disciples share in Christ’s mission and his power, but also in his lot. By all his actions, Christ prepares and builds His Church” (765). 

During his ministry on Earth, Jesus singles out the apostle Simon Bar-Jona to be the head of His new Church, which will exist to the end of time: “And I tell you, you are Peter, and on this rock I will build My Church, and the powers of death shall not prevail against it” (Matt. 16:18; see also John 1:42). With these words, Jesus changes Simon’s name to Peter, which means “rock.” In Aramaic, the language Jesus spoke, Simon’s new name is Kepha (or Cephas), which means a sizable rock usable as a building’s foundation. Kepha is translated into Greek as Petros, from which we get Peter in English. 

Jesus goes on to give Peter special authority over His Church: “I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (CONFESSION) (Matt. 16:19). Peter and the other apostles who hear this proclamation understand these symbolic keys to be Jesus’ Own Authority over His Church in His absence. Such a handing on of kingly authority was known to the Jews and is imaged in the Old Testament foretelling of Eliakim being given authority as King Hezekiah’s royal steward over the kingdom of Israel (Isa. 22:20-22).  

Just as God gives Eliakim the keys to the kingdom of Israel, Jesus gives Peter the keys to his kingdom. And just as Eliakim “shall be a father” to Israel (Isa. 22:21), Peter (and his successors) leads the Church as a spiritual father—as papa, or pope. The authority to “bind and loose” (“open and shut”) is given first to Peter and later to the apostles under him as well. 

The Catechism explains: 

The “power of the keys” designates authority to govern the house of God, which is the Church. Jesus, the Good Shepherd, confirmed this mandate after his Resurrection: “Feed my sheep” (John 21:15-17). The power to “bind and loose” connotes the authority to absolve sins, to pronounce doctrinal judgments, and to make disciplinary decisions in the Church. Jesus entrusted this authority to the Church through the ministry of the apostles and in particular through the ministry of Peter, the only one to whom he specifically entrusted the keys of the kingdom (553). 

Having established an authoritative hierarchy for His Church, Jesus demonstrates that He intends the Church to be a community of believers with a continual, visible hierarchy here on earth. For example, He outlines a procedure involving sinners in the Church:  

If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother. But if he does not listen, take one or two others along with you, that every word may be confirmed by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the Church; and if he refuses to listen even to the Church, let him be to you as a Gentile and a tax collector (Matt. 18:15-17). 

Clearly, Jesus founded the Church as a tight-knit community of disciples with tangible access to the authority of Peter and the apostles. Shortly after the Ascension, this all became manifest to the world: “When the work which the Father gave the Son to do on earth was accomplished, the Holy Spirit was sent on the day of Pentecost in order that he might continually sanctify the Church. Then the Church was openly displayed to the crowds and the spread of the gospel among the nations, through preaching, was begun” (CCC 767). 

[TAKEN FROM - 20 ANSWERS: THE EARLY CHURCH]