The Authority of Scripture and Tradition

The Catholic Church teaches that Divine Revelation is handed down through both Sacred Scripture and Sacred Tradition—two distinct yet inseparable means by which God’s truth is transmitted to His people. This teaching finds clear support in Scripture itself.

St. Paul exhorts the Thessalonians: “So then, brothers, stand firm and hold fast to the traditions that you were taught by us, either by word of mouth or by our letter” (2 Thessalonians 2:15). Here, the apostle explicitly upholds both written and oral forms of teaching as authoritative.

Likewise, he praises the Corinthians for preserving what he had passed on to them: “I commend you because you remember me in everything and maintain the traditions even as I delivered them to you” (1 Corinthians 11:2).

Before the New Testament was written, the apostles faithfully proclaimed the Gospel through preaching, worship, and example—this living Tradition guided the early Church and gave rise to the very Scriptures we now possess.

Thus, Scripture and Tradition flow from the same divine source and together safeguard the fullness of the apostolic faith, under the guidance of the Church’s teaching authority.

The Binding and Loosing Authority of the Catholic Magisterium

The Catholic Church teaches that Christ entrusted His Church with a real authority to bind and loose, which refers to the authority to teach and govern. This authority, exercised by the Magisterium, is rooted in Scripture.

In Matthew 16:19, Christ declares to Peter: “I will give you the keys of the kingdom of heaven; whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.” The imagery of the keys signifies governing authority, echoing Isaiah 22:22 and the office of the steward in the house of David.

This authority is also shared with the apostles collectively when Jesus says to all of them: “Whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (Matthew 18:18). Here Christ affirms that the Church’s judgments carry heavenly ratification.

We see this authority in practice in Acts 15, where the apostles, guided by the Holy Spirit, resolve a major controversy in the early Church, declaring: “It has seemed good to the Holy Spirit and to us…” (Acts 15:28).

Thus, the Magisterium is not merely human leadership but Christ’s own authority exercised through His Church for the sake of unity and truth.

The Real Presence of the Eucharist

The Catholic Church professes that in the Eucharist, the bread and wine truly become the Body and Blood of Christ. This belief rests firmly on the words of Scripture.

In John 6:51, our Lord declares: “I am the living bread which came down from heaven; if anyone eats of this bread, he will live forever; and the bread which I shall give for the life of the world is my flesh.” When His listeners struggled with this teaching, Christ did not soften His words, but emphasized them all the more: “My flesh is true food, and my blood is true drink” (John 6:55).

At the Last Supper, Jesus instituted this gift, saying over the bread, “This is my body” (Luke 22:19), and over the chalice, “This is my blood of the covenant” (Matthew 26:28). He spoke not of mere symbols, but of a true reality.

St. Paul testifies to the same in 1 Corinthians 10:16: “The cup of blessing which we bless, is it not a participation in the blood of Christ? The bread which we break, is it not a participation in the body of Christ?”

Thus, from Christ’s own words and apostolic witness, the Church has always recognized that the Eucharist is the true and abiding presence of the Lord Himself.

Outside the Church there is No Salvation

The Catholic doctrine that there is no salvation outside the Church is often misunderstood. Properly understood, it is a profound affirmation of Christ as the sole source of salvation and of the Church as His Body.   

Our Lord declares: “I am the way, and the truth, and the life. No one comes to the Father except through me” (John 14:6). Salvation is found in Christ alone. Yet Christ also founded a visible Church, saying to Peter, “On this rock I will build my Church, and the gates of Hades shall not prevail against it” (Matthew 16:18).

St. Paul further teaches that Christ is “head over all things to the Church, which is his body, the fullness of him who fills all in all” (Ephesians 1:22–23). To be united with Christ is therefore to be united with His Body, the Church. Acts 2:47 confirms this: “The Lord added to the Church daily those who were being saved.”

The doctrine does not deny God’s mercy toward those outside visible membership of the Church, and are invincibly ignorant of the truth, but moved by grace, seek to follow God according to their conscience. Rather it proclaims that all who are saved are saved through Christ and His Church—the sacrament of salvation for the world.

Priests and the Authority to Forgive Sins

 The Catholic Church’s teaching that priests can forgive sins is not based on human authority, but on the words of Christ Himself. 

In John 20:21–23, the risen Jesus appears to His apostles and says, “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained.” This is not symbolic language. Christ gives His apostles real authority to forgive and retain sins. He says that He is sending the apostles as the Father had sent Him. The word "send" here refers to being sent with the full authority of the sender, which includes the authority to forgive sins.

This ministry of reconciliation is further affirmed in 2 Corinthians 5:18, where St. Paul writes, “All this is from God, who reconciled us to himself through Christ and gave us the ministry of reconciliation.” The apostles, and by extension their successors, are entrusted with carrying out this sacred work.

James 5:14–16 also instructs the faithful to call upon the elders (presbyters or priests) of the Church in times of illness and to “confess your sins to one another,” linking confession to the pastoral care of ordained ministers.

Peter and the Keys of the Kingdom

The office of the Pope finds its foundation in the words of Christ Himself. In Matthew 16:18–19, Jesus declares to Peter, “You are Peter, and on this rock I will build my Church… I will give you the keys of the kingdom of heaven.” This passage reveals not only Peter’s unique role among the apostles, but also Christ’s intention to establish a visible, enduring leadership for His Church.

The imagery of the “keys” echoes Isaiah 22:22, where authority is passed to a steward over the house of David—pointing to Peter as steward over the household of the New Covenant. Though Peter was a man of weakness, Jesus nonetheless chose him to strengthen the brethren (Luke 22:32) and to feed His sheep (John 21:15–17).

In Acts 15, Peter exercises this leadership at the Council of Jerusalem, where his words bring clarity and peace to a divisive matter. From the earliest days, the Church recognized Peter’s primacy, a role continued by his successors in Rome.

The papacy, then, is not a human invention, but a gift from Christ for the unity and guidance of His Church.

The Sinlessness of Mary

The Catholic Church teaches that Mary was preserved from sin by a singular grace of God—not because of her own merit, but in preparation for her unique role as the Mother of the Savior.

In Luke 1:28, the angel Gabriel addresses her as “full of grace” (kecharitōmenē in Greek), a term that signifies a completeness and permanence of divine grace. This unique greeting points to a special work of God in Mary’s soul—one not attributed to any other figure in Scripture.

Just as the Ark of the Covenant was made holy to carry the presence of God (cf. Exodus 25), so too was Mary prepared to bear the Word made flesh. Her purity reflects not her own glory, but the holiness of the One she carried.

Though Romans 3:23 states that “all have sinned,” the Church recognizes that God, in His sovereignty, can act exceptionally—as He did with Christ. Mary’s sinlessness is not a denial of her need for a Savior, but a testimony to the saving power of Christ applied to her in a unique and preemptive way.

Her holiness magnifies the greatness of the Lord (Luke 1:46), who prepared her entirely for the mission of bearing His Son.