And we also thank God constantly for this, that when you received the word of God
which you heard from us, you accepted it not as the word of men but as what it really is,
the word of God, which is at work in you believers.
1 Thessalonians 2, 13
And you also were included in Christ when you heard the message of truth,
the gospel of your salvation. When you believed, you were marked in him with a seal,
the promised Holy Spirit.
Ephesians 1, 13
Follow the pattern of the sound words which you have heard from me, in the faith
and love which are in Christ Jesus; guard the truth that has been entrusted to you
by the Holy Spirit who dwells within us.
2 Timothy 1, 13-14
Sacred Tradition is the unwritten word of God and thus is a source of divine revelation from which even sacred Scripture (the written word of God) proceeds (Lk 1:1-4). By unwritten or verbally unspoken, we mean all the divine mysteries that are revealed or declared by the Holy Spirit to the Church in the passage of time (Jn 16:12-13). It’s because Tradition or God’s unwritten word is infallible that Scripture, God’s written word, is infallible since both sources of divine revelation originate from the Holy Spirit under the Spirit’s guidance (Tradition) or by the Spirit’s inspiration (Scripture). And since the written word proceeds from the initial unwritten word, Scripture must be interpreted in light of Tradition. The former medium serves as an objective norm or confirmation of the latter. Thus, these two mediums of divine revelation comprise two sides of the same coin, and so they mustn’t be divorced from each other or placed in opposition to each other. This isn’t an either/or proposition.
Tradition literally means “handing on” referring to the passing down of God’s revealed word from the beginning under the guidance of the Holy Spirit. Moreover, Tradition means all divine revelation from the dawn of human history to the end of the apostolic age from one generation of believers to the next which is safeguarded by the Church (the Rule of Faith) until Christ returns in glory (Mt 28:20). Tradition may also be said to contain all that is materially presented in Scripture either explicitly or implicitly. It’s because Scripture isn’t always explicit that, as a sole rule of faith, it is formally insufficient. And so, Tradition often reveals or exposes what is explicitly lacking in Scripture but is there nonetheless as a representation of the verbally unspoken word: the declaration of the Holy Spirit. The written word and the unwritten word of God mutually support each other in a complementary way, having originated from the same Divine Author and guarantor of the truth.
Since the beginning, the one, visible Church founded by Christ himself has believed that Sacred Scripture and Sacred Tradition are bound closely together and correspond with one another towards the same goal in a form of symbiotic relationship and that these two mediums of divine revelation flow from the same source, viz. the Holy Spirit ( Jn 14:16, 26; 16:12-13). The Church, therefore, has never drawn its certainty about the revealed divine truths from only sacred Scripture. The apostles understood that their preaching was guided by the Holy Spirit, who protects the Church from error (Acts 15:27-28). And it was Paul who wrote that the Church - not Scripture - is "the pillar and foundation of the truth" (1 Tim 3:15).
So then, brothers and sisters, stand firm and hold fast to the teachings
we passed on to you, whether by word of mouth or by letter.
2 Thessalonians 2, 15
Referring to how Christian tradition was handed on, Vatican ll states: “It was done by the apostles who handed on, by the spoken word of their preaching, by the example they gave, by the institutions they established, what they themselves had received – whether from the lips of Christ, from His way of life and His works, or whether they had learned it from the prompting of the Holy Spirit” (Constitution on Divine Revelation, ll, 7). God was faithful in the transmission of the written word as was evident by the Church’s infallible ruling of which Biblical books and Epistles belonged to the canon of Scripture. Thus, God must also be faithful to His Church in the transmission of His unspoken word declared by the Holy Spirit and preached by the apostles and their anointed successors, which manifests in greater fullness what has been revealed by God and committed to writing.
According to John Cardinal Henry Newman, Scripture and Tradition aren’t two separate “sources” of divine revelation, but rather two “modes” of transmitting the same deposit of faith. In his words: “Totum in scriptura, totum in traditione.” (“All is in Scripture, all is in Tradition.”). These two mediums point towards and embrace each other as constituting together in a single expression the word of God. If Paul had committed everything he preached to his letters, he would have written 'by word of mouth and by letter.
Hence, the entire body of Christ - from the laity to the bishops - have an anointing which originates from the Holy Spirit (1 Jn 2:20, 27). Being members of one mystical body with Christ as the head they cannot be deceived as our Lord had promised his apostles. This feature of the Church is shown in the supernatural appreciation of the faith (sensus fidei) by all the faithful when they manifest a universal consent in matters of faith and morals. And by this appreciation of the faith, aroused and sustained by the Spirit of truth, the entire people of God's household, guided by the Magisterium and obeying it, receive not the mere word of men, but truly the word of God declared by the Holy Spirit (1 Cor 2:13); the faith delivered once for all (cf. Lumen Gentium, 12). "What the body of the Church together with its pastors, agreed in holding as of faith, is part of revelation; since the Church is filled and assisted by the Holy Spirit and cannot be wrong on a matter of faith. This has always been the conviction of the Catholic Church both eastern and western" (Yves Congar, Tradition and Traditions: 1966).
The word is near you, even in your mouth, and in your heart:
that is, the word of faith, which we preach.
Romans 10, 8
On Pentecost, the Church was established as a single and visible historical reality with the descent of the Holy Spirit. It was only then that an unfolding revelation first received by the apostles could be transmitted to future generations under the promised guidance of the Paraclete. The divine truth in all its manifestations and growing fullness has carried with it ever since the seal of the Holy Spirit whose sanctifying presence guarantees the purity of faith in the Church - the "unblemished" body of Christ. Thus, the seed which has been planted by the apostles must be abided by and sustained through an increase of knowledge and understanding of the Divine mysteries through the inspiration and assistance of the Holy Spirit. The truth in all its fullness does not exist outside the Catholic Church, where there is neither Scripture nor Tradition apart from whatever capital has been borrowed by non-Catholic believers from the Church (Acts 1:8-9).
In the words of the 5th-century monk, Vincent of Lerins: "We must hold what has been believed everywhere, always, and by all." Tradition has been described as timeless although situated in temporal reality. It is an ongoing memory of the whole Church (the one timeless mystical body of Christ) whose principal aim isn't to restore the past but better understand it in the present and recollect it in a greater light of faith beyond the limits of time. This memory consists not only of words, written or spoken but also of how they have been assimilated and expressed liturgically by all the faithful through the centuries and passed on. Tradition is a living experience that is relived and renewed over time but adversely unaffected by it without any adulteration of a divine truth presented as a gift of the Holy Spirit.
Tradition is the work of God through which He continues to reveal in greater measure to His Church what has been revealed and worded in the Scriptures. Hidden implications in the inspired sacred writings come to light through the handing down of Tradition. The Church's fundamental doctrines have developed over time with deepening reflection and pondering of the heart under the guidance of the Holy Spirit. The word of God isn't altered or fabricated but rather better understood in time through timeless Tradition under with the guaranty of the promised Paraclete. The deposit of faith was planted by the apostles in the form of a seed from which one and the same flower has continued to grow and blossom from one mysterious aspect to another. The definition of an article of faith (i.e., The Holy Trinity or the Immaculate Conception of Mary) resembles an entire work of mosaic art pieced together one tile at a time.
St. Paul forcefully stated that he was passing on something that was “handed on” to him (1 Cor 11:23). He knew and appreciated that the community of believers whom he was addressing had a strong sense of what was important enough to be passed on to the next generation of believers, who in turn would abide by and preserve the Faith. He believed the Holy Spirit would help the entire communities understand in unison what in their experiences and practices should really be held on to in light of their vision of God’s plan of redemption. This would include the virgin birth, which Paul never mentioned in any of his writings. And it must have included the Assumption of Mary as well among many other articles of faith. The apostle called the Church a “mystery” which meant that, as the kingdom of God in our midst, it could not be understood by reason alone (Eph 5:32). God’s infinite wisdom which is revealed through His word is a hidden mystery for all ages, which can be made known more fully over the passage of time only through the one true Church founded by Christ on Peter and the Apostles under the guidance of the Holy Spirit (Mt 16: 15-18; Eph 3:9-10).
Early Sacred Tradition
“Since, therefore, the tradition from the apostles does thus exist in the Church, and is
permanent among us, let us revert to the Scriptural proof furnished by those apostles who did
also write the Gospel, in which they recorded the doctrine regarding God, pointing out that
our Lord Jesus Christ is the truth, and that no lie is in Him.”
Irenaeus, Against Heresies 3,5,1
(inter A.D. 180-189)
“Now the cause, in all the points previously enumerated, of the false opinions, and of the
impious statements or ignorant assertions about God, appears to be nothing else than the not
understanding the Scripture according to its spiritual meaning, but the interpretation of it
agreeably to the mere letter. And therefore, to those who believe that the sacred books are
not the compositions of men, but that they were composed by inspiration of the Holy Spirit,
agreeably to the will of the Father of all things through Jesus Christ, and that they have come
down to us, we must point out the ways (of interpreting them) which appear (correct) to us, who
cling to the standard of the heavenly Church of Jesus Christ according to the succession of
Origen, First Principles, 4,1:9
"But in learning the Faith and in professing it, acquire and keep that only, which is now
delivered to thee by the Church, and which has been built up strongly out of all the Scriptures
... Take heed then, brethren, and hold fast the traditions ye now receive."
Cyril of Jerusalem, Catechetical Lectures 5:12
"But beyond these Scriptural sayings, let us look at the very tradition,
teaching, and faith of the Catholic Church from the beginning, which the
Lord gave, the apostles preached, and the Fathers kept."
Athanasius, Four Letters to Serapion of Thumius 1:28
“I have yet many things to say to you, but you cannot bear them now.
When the Spirit of truth comes, he will guide you into all the truth; for he
will not speak on his own authority, but whatever he hears he will speak,
and he will declare to you the things that are to come.”
John 16, 12-13