The Catholic Church does not rely upon Scripture alone. If it did, there would have been a real problem for the first 400 years of Christianity as there was no written New Testament. Yes, the Apostles and the other Sacred writers had written things down but it was not until the councils of Rome, Hippo and Carthage that the New Testament was put together. It is the authority of the Catholic Church that gives the world the New Testament and it was not until Luther that someone inserted their own word into Sacred Scripture.
Sacred Tradition is defined as the oral teachings of Jesus Christ handed down to His Apostles and, through His Church, to us via the Magisterial Teachings. Interestingly enough, those who hold to a Bible Alone theology miss places in the Sacred texts that uphold the idea of Oral Teachings and Sacred Tradition.
For instance, in Acts 20:35, St. Paul says the following:
"In all things I have shown you that by so toiling one must help the weak, remembering the words of the Lord Jesus, how he said, `It is more blessed to give than to receive.'"
The words attributed to Jesus are not recorded anywhere else in the New Testament. St Paul learned these words from those who taught him the faith after his conversion.
In the book of Jude 1:9 an interesting exchange between St Michael the Archangel and Satan is reported. They are disputing over Moses' body and that dispute is not recorded anywhere in the Old Testament.
In the Gospel according to St Matthew a prophecy is referred to ("he shall be called a Nazarene") that is not recorded anywhere else in The Bible.
Finally, the Tradition of holding the Lord's Day as holy - and on Sunday - is excepted by true Christians (not those who reject the Trinity) and that is a Sacred Tradition passed down from the beginning of The Church.
Today we celebrate the Feast of the Presentation of Our Lady. From the very beginning Christians knew that Our Lady was someone pretty special. Saved through the merits of Jesus Christ from the moment of her conception, she remained sinless her entire life. Espoused to the Holy Spirit and the Mother of God, she was under the protection of St Joseph, her most chaste spouse, a man willing to put himself between her, The Child, and the world rather than satisfy his own wants and needs.
We know of this feast through Sacred Tradition. We understand the significance of this feast because it sets the stage for Salvation History. The action of dedicating their only child to the Temple protected her from outside pressures of the society of the day - the pressure to marry, to have lots and lots of children, to put her attention on what the law demanded rather than what God asked.
Mary, conceived without sin, became at her conception the Sacred Vessel crafted by God through the creative cooperation of her parents. When she was overshadowed by The Holy Spirit, she became the Ark of the New Covenant, the New Eve. Like the Ark of the Covenant (which carried manna from heaven, the rod of Aaron and the broken tablets of the 10 commandments) she carried within her womb the Food from Heaven, the Authority of God and the Law in the person of Jesus Christ - True God and True Man.
Today let's take a moment and thank the parents of Our Lady, St Anne and St Joachim, for dedicating their only child to God. Let's thank them for their role in Salvation History and let's vow to make our role in that same history a vital and real one.
Our Lady Queen of Peace, pray for us!