“Sacred Tradition is the very Church; without the Sacred Tradition the Church does not exist. Those who deny the Sacred Tradition deny the Church and the preaching of the Apostles.
Before the writing of the Holy Scriptures, that is, of the sacred texts of the Gospels, the Acts and the Epistles of the Apostles, and before they were spread to the churches of the world, the Church was based on Sacred Tradition....The holy texts are in relation to Sacred Tradition what the part is to the whole.
The Church Fathers regard Sacred Tradition as the safe guide in the interpretation of Holy Scripture and absolutely necessary for understanding the truths contained in the Holy Scripture. The Church received many traditions from the Apostles... The constitution of the church services, especially of the Divine Liturgy, the holy Mysteria themselves and the manner of performing them, certain prayers and other institutions of the Church go back to the Sacred Tradition of the Apostles.
In their conferences, the Holy Synods draw not only from Holy Scriptures, but also from Sacred Tradition as from a pure fount. Thus, the Seventh Ecumenical Synod says in the 8th Decree: "If one violates any part of the Church Tradition, either written or unwritten, let him be anathema."
- Saint Nektarios of Aegina