Sacred Scripture refers to the Bible, which is considered the inspired word of God. It is integral to Catholic doctrine, as it encapsulates the divine revelations essential for understanding God's will, the teachings and life of Jesus Christ, the moral and ethical guidelines for living a faithful life, and the historical foundation upon which the Church's traditions and teachings are built.

The first formal canonization of the bible was spearheaded by the Catholic Church, effectively becoming the first institution to do so. Prior to this pivotal moment, there existed no universally recognized or formalized Bible, necessitating a comprehensive effort to compile and authenticate sacred texts. It was a monumental task for the Catholic Church, but with the guidance of Sacred Tradition, which includes the teachings of the apostles, they were able to discern, preserve, and transmit the authentic writings that would form the definitive canon of Sacred Scripture.

Specifically, the Council of Rome in AD 382, convened under the auspices of Pope Damasus I, played a central role in this process, deliberating and finalizing the list of canonical books with meticulous care. Subsequent synods, notably the Synods of Hippo (AD 393) and Carthage (AD 397 and 419), reinforced and ratified these decisions, affirming the sacredness and divine inspiration of specific biblical writings. These councils, guided by influential figures such as St. Augustine, contributed significantly to the establishment of a standardized Bible, ensuring its widespread acceptance and reverence within the Christian community.

During the Council of Rome, several books underwent consideration for inclusion in the biblical canon but were ultimately omitted. While not exhaustive, among these were the Gospel of Thomas, Gospel of Peter, and Epistle of Barnabas. These texts presented doctrinal inconsistencies; for instance, the Gospel of Peter's portrayal of the cross as speaking directly to God during Jesus' crucifixion diverged significantly from established Church teachings. Conversely, the Didache, which to this day remains an important historical and theological document respected by the Church; it is recognized as an early manual outlining Christian practices and beliefs and is consistent with early Church teachings, its exclusion stemmed primarily from the Church's prioritization of texts with clear apostolic origin for inclusion in the canon.

Through their collective endeavors and the endorsement of papal authority, the Catholic Church provided a unified and authoritative foundation for the Christian faith, shaping the course of religious history for centuries to come and laying the cornerstone for the Bible as we know it today.

Sacred Tradition, an integral facet of Catholic belief, assumes paramount importance in preserving and transmitting divine teachings, particularly during an era devoid of a formalized, canonized Bible, which persisted until the Catholic Church officially canonized the Bible in AD 382. In the absence of a universally accepted scripture, Sacred Tradition served as the primary vehicle for safeguarding and disseminating essential doctrines, ensuring their continuity across generations.

It was through this rich tapestry of oral teachings, rituals, and practices, passed down from apostolic times, that the core tenets of Christianity found expression and vitality. The early Christian community relied heavily on the fidelity of Sacred Tradition, which functioned as a living link to the teachings of Jesus Christ and His apostles. Recognizing the indispensability of this tradition, the Catholic Church esteemed it alongside Sacred Scripture, acknowledging their complementary roles in shaping and elucidating divine revelation.

Through the discernment and guidance of the Holy Spirit, the Church preserved the integrity of Sacred Tradition, upholding its significance as a sacred deposit of faith. Thus, in the absence of a codified Bible, Sacred Tradition played a pivotal role in establishing and nurturing Christian communities, with the apostles themselves serving as the foundation upon which the Church was built, rather than interpretations derived solely from written texts.

The term "Catholic Church" began to emerge in the early Christian writings, particularly in the second century. One of the earliest known mentions is found in the writings of Ignatius of Antioch, a disciple of the Apostle John, who lived around AD 35-110. In his letter to the Smyrnaeans, Ignatius wrote, "Wherever the bishop shall appear, there let the multitude [of the people] also be; even as, wherever Jesus Christ is, there is the Catholic Church" (Letter to the Smyrnaeans, Chapter 8). This indicates that by the early second century, the term "Catholic Church" was already in use to describe the universal Christian community.

The Early Church Fathers, such as Ignatius of Antioch, Clement of Rome, and Irenaeus of Lyons, played a vital role in preserving Sacred Tradition from the time of Jesus. Drawing upon the teachings of the apostles, these early Christian leaders defended and elucidated the core tenets of the faith, ensuring their fidelity to the original apostolic deposit. Amidst persecution and doctrinal challenges, these figures steadfastly upheld and passed down the teachings they had received, safeguarding them from distortion or corruption.

The importance of Sacred Tradition is underscored by Jesus Christ himself in several passages of the New Testament:

• 2 Thessalonians 2:15: "So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter."
• 1 Corinthians 11:2: "I commend you because you remember me in everything and maintain the traditions even as I have delivered them to you."
• 2 Timothy 2:2: "and what you have heard from me before many witnesses entrust to faithful men who will be able to teach others also."

Hence, the Catholic Church is called an apostolic church due to its direct lineage tracing back to the teachings of the apostles, carefully preserved and transmitted through Sacred Tradition. This apostolic succession finds further validation through the unbroken line of bishops of Rome, known as the popes, who are acknowledged as the spiritual heirs of Saint Peter, the foremost apostle chosen by Jesus Christ.

Saint Irenaeus of Lyons, an eminent Church Father and a disciple of Polycarp, himself a direct disciple of the apostle John, reinforces this apostolic tradition in his work 'Against Heresies.' In this, he underscores the preeminence of the Church at Rome, established by the apostles Peter and Paul. He affirms its enduring adherence to apostolic doctrine and its pivotal role in preserving the faith across generations.

Irenaeus unequivocally asserts, 'It is incumbent upon every Church to be in agreement with this Church, on account of its superior authority, in which the apostolic tradition has been preserved continuously by those faithful men who exist everywhere' (Against Heresies, Book 3, Chapter 3, Verse 2) [AD 180-185]. By emphasizing the universal authority vested in the Church at Rome, he emphasizes the unity and steadfastness of the Catholic Church in upholding the sacred deposit of faith passed down from the apostolic era.