Of the teachings and proclamations preserved in the Church, some we possess from written teaching, while others we have received in secret from the Tradition of the Apostles; these both have the same validity [ie. authority] for true religion. And no one will deny these points, at least if he is even moderately experienced in Church [matters].
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.
Let us avail ourselves of the example of that holy staretz who used to say: 'Depart, evil one; come, beloved!' Once a brother who overheard his words and supposed that the staretz was speaking to another man asked him 'With whom are you conversing, father?' And the staretz answered: 'I am driving away evil thoughts and calling the good ones to my side.' And so, if we are tempted, let us use the words of that staretz, or others like them.
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
You have no peace from thoughts, which impel you to trouble others, and in turn to be troubled by others. But know, my brother, that if we offend by word or deed, we are thereby ourselves offended a hundredfold. Be longsuffering in all things and refrain from letting your own will enter into anything. Carefully examine your thoughts lest they infect your heart with deadly poison (ill temper) and make you take a gnat for a camel, a pebble for a cliff, and lest you become like a man who has a beam in his own eye but beholds the mote in the eye of another.
When an archer desires to shoot his arrows successfully, he first takes great pains over his posture and aligns himself accurately with his mark. It should be the same for you who are about to shoot the head of the wicked devil. Let us be concerned first for the good order of sensations and then for the good posture of inner thoughts.
Observe your thoughts, and beware of what you have in your heart and your spirit, knowing that the demons put ideas into you so as to corrupt your soul by making it think of that which is not right, in order to turn your spirit from the consideration of your sins and of God.
They (namely the Apostles) have not handed down everything in writing, but have also delivered many things in unwritten form. The former and the latter are equally trustworthy, and so we also consider the [unwritten] Tradition of the Church to be trustworthy. Is it Tradition? Seek no further.
When despondency seizes us, let us not give in to it. Rather, fortified and protected by the light of faith, let us with great courage say to the spirit of evil: 'What are you to us, you who are cut off from God, a fugitive for Heaven, and a slave of evil? You dare not do anything to us: Christ, the Son of God, has dominion over us and over all. Leave us, you thing of bane. We are made steadfast by the uprightness of His Cross. Serpent, we trample on your head.'
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.