Catholic Tradition often seems odd to those outside the Catholic Church.
People assume it's something that we just... "made up."
Sacred Tradition comes from Christ. It's the full, living gift of Christ to the Apostles, faithfully handed down through each generation. It is through Tradition that the Holy Spirit makes the Risen Lord present among us, offering us the very same saving Word and Sacraments that he gave to the Apostles!
Understanding Catholic Tradition is essential to understanding the Catholic Church and the Catholic Christian faith.
Tradition is "handed down"
The word "tradition" actually means handing down something to another person.
Scripture testifies to this meaning of Catholic Tradition as the normal mode of transmitting the Faith:
"So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter." (2 Thess 2:15)
"For I received from the Lord what I also handed on to you...." (1 Cor 11:23)
"For I handed on to you as of first importance what I also received...." (1 Cor 15:3)
"...I know whom I have believed [i.e., Jesus], and I am sure that he is able to guard until that Day what has been entrusted to me. Follow the pattern of the sound words which you have heard from me, in the faith and love which are in Christ Jesus; guard the truth that has been entrusted to you by the Holy Spirit who dwells within us." (2 Tim 1:11-14)
"You then, my son, be strong in the grace that is in Christ Jesus, and what you have heard from me before many witnesses entrust to faithful men who will be able to teach others also." (2 Tim 2:1-2)
"...I found it necessary to write appealing to you to contend for the faith which was once for all delivered to the saints." (Jude 1:3)
This is the most basic meaning of Catholic Tradition: it is the true Faith itself, given to the Apostles by Christ and faithfully transmitted to each new generation. (Catechism, 77-78)
We often write Tradition, with a capital 'T', to mean Sacred Tradition. This Catholic Tradition is different from those traditions (small 't') that are merely customs, and which are not part of Divine Revelation.
The Apostolic source of Catholic Tradition
The Second Vatican Council ("Vatican II") wrote an important document called "On Divine Revelation" (Dei Verbum in Latin). It's quite readable, and contains definitive teaching on the full meaning of Catholic Tradition.
The Council notes the importance of seeing that Catholic Tradition is firmly rooted in the Apostles: it is Christ's whole gift to them, and to us. The Council writes:
In His gracious goodness, God has seen to it that what He had revealed for the salvation of all nations would abide perpetually in its full integrity and be handed on to all generations. Therefore Christ the Lord in whom the full revelation of the supreme God is brought to completion..., commissioned the Apostles to preach to all men that Gospel which is the source of all saving truth and moral teaching, and to impart to them heavenly gifts.
(_Dei Verbum_, 7)
It is specifically this "commissioning of the Apostles" that is fulfilled in the handing on of Catholic Tradition.
The Apostles dedicated themselves to this mission, and they appointed other faithful men to succeed them and carry on their work. That same passage of Dei Verbum continues:
This commission was faithfully fulfilled by the Apostles who, by their oral preaching, by example, and by observances handed on what they had received from the lips of Christ, from living with Him, and from what He did, or what they had learned through the prompting of the Holy Spirit. The commission was fulfilled, too, by those Apostles and apostolic men who under the inspiration of the same Holy Spirit committed the message of salvation to writing.
(_Dei Verbum_, 7)
Catholic Tradition and Scripture
Many Protestants believe that Catholics look to Tradition instead of Scripture.
Not at all!
Catholic Tradition stands with Scripture in forming the one single deposit of the Faith. For Catholics, Sacred Tradition is not in opposition to Scripture: they compliment and confirm one another.
Vatican II's Dei Verbum speaks of "a close connection and communication between sacred tradition and Sacred Scripture": "both of them... [flow] from the same divine wellspring."
It says that "Sacred Scripture is the word of God inasmuch as it is consigned to writing under the inspiration of the divine Spirit, while sacred tradition takes the word of God entrusted by Christ the Lord and the Holy Spirit to the Apostles, and hands it on to their successors in its full purity." The Church, "led by the light of the Spirit of truth, ...may in proclaiming it preserve this word of God faithfully, explain it, and make it more widely known." (Dei Verbum, 9)
This statement reveals another key aspect of Catholic Tradition: it is linked to the active work of the Holy Spirit.
The living experience of Christ through the Spirit
Pope Benedict XVI gave a beautiful catechesis on Catholic Tradition in late April, 2006. He says that we miss the profound meaning of Catholic Tradition if we see it only as the handing on of a static Revelation.
More than that, it is the active, continuous work of the Holy Spirit in our particular time: it makes real and tangible "the active presence of the Lord Jesus in his people, realized by the Holy Spirit".
Seeing Catholic Tradition as the active presence of Christ through the work of the Spirit is precisely what accomplishes the "transmission of the goods of salvation" to us:
Thanks to Tradition, guaranteed by the ministry of the apostles and their successors, the water of life that flowed from the side of Christ and his saving blood comes to the women and men of all times. In this way, Tradition is the permanent presence of the Savior who comes to meet, redeem and sanctify us in the Spirit through the ministry of his Church for the glory of the Father.
This reality of the divine action of the Holy Spirit within the Church is essential to understanding Catholic Tradition. It is what makes Sacred Tradition something far different than mere human traditions.
Through that same action of the Spirit, Catholic Tradition incorporates us into the Communion of the Saints. It ensures the connection "between the experience of the apostolic faith, lived in the original community of the disciples, and the present experience of Christ in his Church."
The Pope concludes:
Tradition is the living river that unites us to the origins, the living river in which the origins are always present, the great river that leads us to the port of eternity. In this living river, the word of the Lord...: "And behold, I am with you always, until the end of the age", is fulfilled again (Matthew 28:20).
Through Catholic Tradition, the Holy Spirit works to bring the grace and truth of Christ into our own lives.
It's real. And it's living right now in the Catholic Church!