Sacred tradition, or holy tradition, is a theological term used in the major Christian traditions, primarily those claiming apostolic succession, such as the Catholic, Eastern Orthodox, Oriental Orthodox, Assyrian, and Anglican traditions, to refer to the foundation of the doctrinal and spiritual authority of Christianity and of the Bible.
Christians believe that the teachings of Jesus and the Apostles were preserved in the scriptures as well as by word of mouth and were handed on. This perpetual handing on of the tradition is called the "Living Tradition"; it is believed to be the faithful and constant transmission of the teachings of the Apostles from one generation to the next. That "includes everything which contributes towards the sanctity of life and increase in faith of the People of God; and so the Church, in her teaching, life and worship [the Creeds, the Sacraments, the Magisterium, and the Holy Sacrifice of the Mass], perpetuates and hands on to all generations all that she herself is, all that she believes." The Deposit of Faith (Latin: fidei depositum) refers to the entirety of divine revelation. According to Roman Catholic theology, two sources of revelation constitute a single "Deposit of Faith", meaning that the entirety of divine revelation and the Deposit of Faith is transmitted to successive generations in scripture and sacred tradition (through the teaching authority and interpretation of the Church's Magisterium (which consists of the Church's bishops, in union with the Pope), typically proceeding synods and ecumenical councils).
In Eastern Orthodox theology, Holy Tradition is the inspired revelation of God and catholic teaching (Greek katholikos, "according to the whole") of the Church, not an independent source of dogmatic authority to be regarded as a supplement to biblical revelation. Tradition is rather understood as the fullness of divine truth proclaimed in the scriptures, preserved by the apostolic bishops and expressed in the life of the Church through such things as the Divine Liturgy and the Holy Mysteries (Eucharist, baptism, marriage, etc.), the Creed and other doctrinal definitions of the First seven ecumenical councils, canonical Christian iconography, and the sanctified lives of godly men and women.
According to the Christian theological understanding of these Churches, 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. Thus, the Bible must be interpreted within the context of sacred tradition and within the community of the church. That is in contrast to many Protestant traditions, which teach that the Bible alone is a sufficient basis for all Christian teaching (a position known as sola scriptura).
Usage of term
The word tradition is taken from the Latin trado, tradere, meaning "to hand over, to deliver, to bequeath". In 2 Thessalonians 2:15, Paul exhorted the faithful to "keep the traditions that we taught you, whether by word of mouth or by letter." Paul's letters form part of Sacred Scripture; what he passed on "by word of mouth" is part of Sacred Tradition, handed down from the apostles. Both are the inspired word of God; the latter helps to inform understanding of the former. Sacred Tradition can never be in conflict with Sacred Scripture.