The Catholic Church does indeed provide the fullness of faith in the revelation of Christ.
To know Christ, we look to the history of salvation of people. We do that through the Word of God – in how it is lived out with the people, not a stand-alone Bible text.
The Church looks to faith as God coming to a gathering of people with shared view of God and lawful authority in providing and affirming that what they understand of God is truth, and not someone’s interpretation that can only bring division and dissension among people of faith.
The Catholic Church is apostolic, meaning that we come to know Christ through the Oral Tradition – the Apostles being sent out to witness Christ after being chosen and formed by Him, living with Him and dialoguing, arguing, clarifying Who He is and His mission.
The Catholic Church follows the Septuagint interpretation to this day – the very one the Apostles and St. Paul had followed from ancient texts that anticipated the nature and mission of Jesus Christ.
The next part of truth of Jesus Christ is then, how was the apostolic faith transmitted and passed down. This is called Sacred Tradition, that is so often misunderstood by non-denominational Christians who have lost faith in the 7 sacraments, only having the one initial sacrament of Baptism. The concrete reality here is the one who baptizes using water and rite words…affirming creed in the Trinity.
When the Glorified Lord entered the throne of heaven before the Heaven Father, His entrance released the Holy Spirit at Pentecost and thus the birth of Christ’s Church.
Early Christians were baptized and confirmed in Christ — confirmation strengthening their faith and assisting them not to denounce Christ in the face of terrible persecutions and death. Many were sustained daily by the reception of the Eucharist.
To receive baptism is indeed a Catholic rite of initiation and those who receive Trinitarian baptism are received into the Mystical Body of Christ, and the Mystical Church. But they become full members when they affirm the faith of Christ in the Eucharist.
To us, Sacred Scriptures lead and are fulfilled in Jesus Christ, and it is Jesus Christ Who is speaking to us through Sacred Scripture, Jesus is LOGOS…the Living Word of God, and that is fulfilled in Jesus, the Word Made Flesh.
You cannot enter into the sacred mystery of Christ without His flesh for the complete revelation of Him to us, and the Eucharist must be provided to us by those consecrated by Him with the laying on of hands by licit bishops in communion with the Holy Father and other bishops. The Orthodox have licit Eucharist but are in schism.
The chosen books of Sacred Scripture, the Liturgy as Christ’s fulfilled worship, the administration of the Church by bishop, presbyter, deacon and priest, and the composition of the Creed were intact by 100 AD, and this structure of Church has been intact for 2,000 years.
The final revelation of Christ was in Nicea…the Nicene Creed, Jesus Christ, True God and True Man, of one substance with the Father, Alpha and Omega, with no beginning or end, St. Athanasius.
St Peter exhorted us to listen to them the apostles, Christ’s chosen witnesses…not one man or two, but the 12…communion!! And to avoid personal interpretation.
When we have Holy Father, bishops in communion, we enter into the most full communion with the Holy Trinity, the goal of every faithful believer.
The essence of Catholicism then is communion, sacred communion with God and with each other and with God’s creation.
When Sacred Scripture is removed from the Church and Sacred Tradition – the other means to show Christ in praxis…how the Church was implemented and grew generation after generation, then you reduce Logos to man’s interpretation, divisions, and the loss of certitude with faith, always doubting and never really finding the concrete of God among us – the sacraments.