Sacred Tradition or Holy Tradition is a technical theological term used in some Christian traditions, primarily in the Roman Catholic, Anglican, Eastern Orthodox and Oriental Orthodox traditions, to refer to the fundamental basis of church authority.
The word "tradition" is taken from the Latin 'trado, tradere' meaning to hand over, to deliver, or to bequeath. The teachings of Scripture are written down in the Bible, and are handed on, not only in writing, but also in the lives of those who live according to its teachings. The teachings of Tradition are not written down, but are lived and are handed on by the lives of those who lived according to its teachings, according to the example of Christ and the Apostles (1 Corinthians 11:2, 2 Thessalonians 2:15). This perpetual handing on of the teachings of Tradition is called a living Tradition; it is the transmission of the teachings of Tradition from one generation to the next.
The term "deposit of faith" refers to the entirety of Jesus Christ's revelation, and is passed forward to successive generations in two different forms, Sacred Scripture (the Bible) and Sacred Tradition (apostolic succession).
In the theology of these churches, Sacred Scripture, is the written part of this larger tradition, recording (albeit sometimes through the work of individual authors) the community's experience of God or more specifically of Jesus Christ. Hence the Bible must be interpreted within the context of Sacred Tradition and within the community of the church.
Sacred Tradition, and thus Sacred Scripture as well, are "inspired," another technical theological term indicating that they contain and communicate the truths of faith and morals God intended to make known for mankind's salvation.
This is in contrast to many Protestant traditions, which believe that the Bible alone is a sufficient basis for all Christian teaching (a position known as Sola Scriptura) and that an individual Christian alone can interpret the Bible- and it is always open to interpretation.
In the English language, "Sacred Tradition" is more likely to be used in reference to Roman Catholicism and "Holy Tradition" in reference to Eastern Orthodoxy, although the two terms are interchangeable in meaning.
Among the earliest examples of the theological appeal to tradition is the response of early 'orthodox' Christianity to Gnosticism, a movement that used some Christian Scripture as the basis for its teachings. Irenaeus of Lyons held that 'rule of faith' (regula fidei) is preserved by a church through its historical continuity (of interpretation and teaching) with the Apostles.  Tertullian argued that although interpretations founded on a reading of all Holy Scripture are not prone to error, tradition is the proper guide.  Athanasius held that Arianism fell into its central error by not adhering to tradition. 
- Sacred Tradition and Sacred Scripture form one sacred deposit of the word of God, committed to the Church. Holding fast to this deposit the entire holy people united with their shepherds remain always steadfast in the teaching of the Apostles, in the common life, in the breaking of the bread and in prayers (see Acts 2, 42, Greek text), so that holding to, practicing and professing the heritage of the faith, it becomes on the part of the bishops and faithful a single common effort.
- But the task of authentically interpreting the word of God, whether written or handed on, has been entrusted exclusively to the living teaching office of the Church, whose authority is exercised in the name of Jesus Christ. This teaching office is not above the word of God, but serves it, teaching only what has been handed on, listening to it devoutly, guarding it scrupulously and explaining it faithfully in accord with a divine commission and with the help of the Holy Spirit, it draws from this one deposit of faith everything which it presents for belief as divinely revealed.
- It is clear, therefore, that Sacred Tradition, Sacred Scripture and the teaching authority of the Church, in accord with God's most wise design, are so linked and joined together that one cannot stand without the others, and that all together and each in its own way under the action of the one Holy Spirit contribute effectively to the salvation of souls.
Thus, all of the teachings of the Catholic Church come from either Tradition or Scripture, or from the Magisterium interpreting Tradition and Scripture. These two sources, Tradition and Scripture, are viewed and treated as one source of Divine Revelation, which includes both the deeds of God and the words of God:
- This plan of revelation is realized by deeds and words having in inner unity: the deeds wrought by God in the history of salvation manifest and confirm the teaching and realities signified by the words, while the words proclaim the deeds and clarify the mystery contained in them. (Dei Verbum, n. 2)
The Magisterium has a role in deciding authoritatively which truths are a part of Sacred Tradition. However, the main means of transmission of the teachings of Tradition is the lives of all those who live according to the Way of life handed down from the time of Christ and the Apostles.
Holy Tradition in the Eastern Orthodox Churches
Holy Tradition, for the Eastern Orthodox, is the deposit of faith given by Jesus Christ to the Apostles and passed on in the Church from one generation to the next without addition, alteration or subtraction. Vladimir Lossky famously described the Tradition as "the life of the Holy Spirit in the Church." It is dynamic in application, yet unchanging in dogma. It is growing in expression, yet ever the same in essence.
The Eastern Orthodox churches does not regard Holy Tradition as something which grows and expands over time, forming a collection of practices and doctrines which accrue, gradually becoming something more developed. Rather, Eastern Orthodox believers view Holy Tradition as being the faith which Jesus Christ taught to the Apostles and which they gave to their disciples, without any development or deepening of understanding in the faith. The Catholic Church, too, views Holy Tradition as a passing down of that same Apostolic Faith, but holds that the Faith continues to deepen and develop over time, all the while staying the same; thus the doctrine of the Trinity, the two natures of Christ, the divine motherhood of Mary, and other central Catholic Christian doctrines were not fully defined until many years after Christ had ascended and the Apostles had died. A common metaphor used to explain this phenomenon is to think of a seed: over time, it grows into a tall oak, but its identity and essence is still the same.
- Analogy of faith
- Sola scriptura - The view that Scripture is the only sufficient rule for deciding issues of faith and practices that involve doctrines.
- Prima scriptura - tradition is given weight, but the Bible takes precedence
- McGrath, Alistair. 1998. Historical Theology: An Introduction to the History of Christian Thought. Oxford: Blackwell Publishers. Chapter 1 'The Patristic Period, c. 100-451.'
- McGrath. op.cit. pp. 29-30.
- McGrath. op.cit. p. 30.
- McGrath. op.cit. p. 30.
- "Tradition and Traditions", in Leonid Ouspensky and Vladimir Lossky, The Meaning of Icons, (Olten, Switzerland: Urs Graf-Verlag, 1952), 17, in the revised edition (Crestwood, NY: St Vladimir's Seminary Press, 1982), 15.
- Paradosis : The Handing On of Divine Revelation
- Sacred Oral Tradition by John Salza
- Tradition and History
- Sacred Scripture and Sacred Tradition Numerous papers by Dave Armstrong