It is through the Sacred Scripture and Tradition that God reveals Himself and His ways. Christian revelation is contained in Scripture and Tradition. Tradition is the process by which divine revelation, coming from Jesus Christ through the apostles, is communicated and unfolded in the community of the Church. Jesus Himself has entrusted His mission and message to His disciples and has given them the guarantee in the fulfillment of their task. So He made the living Church the medium through which His saving message should reach mankind: “Go therefore and make disciples of all nations ... and I am with you always to the close of age” (Mt 28:19).
The Catechism of the Catholic Church summarizes it thus:
80 "Sacred Tradition and Sacred Scripture, are bound closely together and communicate one with the other. For both of them, flowing out from the same divine well-spring, come together in some fashion to form one thing and move towards the same goal." Each of them makes present and fruitful in the Church the mystery of Christ, who promised to remain with his own "always, to the close of the age."
81 "Sacred Scripture is the speech of God as it is put down in writing under the breath of the Holy Spirit."
"And [Holy] Tradition transmits in its entirety the Word of God which has been entrusted to the apostles by Christ the Lord and the Holy Spirit. It transmits it to the successors of the apostles so that, enlightened by the Spirit of truth, they may faithfully preserve, expound, and spread it abroad by their preaching."
96 What Christ entrusted to the apostles, they in turn handed on by their preaching and writing, under the inspiration of the Holy Spirit, to all generations, until Christ returns in glory.
97 "Sacred Tradition and Sacred Scripture make up a single sacred deposit of the Word of God" (DV 10), in which, as in a mirror, the pilgrim Church contemplates God, the source of all her riches.
98 "The Church, in her doctrine, life, and worship, perpetuates and transmits to every generation all that she herself is, all that she believes" (DV 8 § 1).
99 Thanks to its supernatural sense of faith, the People of God as a whole never ceases to welcome, to penetrate more deeply, and to live more fully from the gift of divine Revelation.
100 The task of interpreting the Word of God authentically has been entrusted solely to the Magisterium of the Church, that is, to the Pope and to the bishops in communion with him.