The “special” revelation of the Bible continues in a preaching rooted in discipleship. And as we read in this section of Dei Verbum, tradition has a twofold purpose: holiness of life and an increase in faith.
And so the apostolic preaching, which is expressed in a special way in the inspired books, was to be preserved by an unending succession of preachers until the end of time. Therefore the Apostles, handing on what they themselves had received, warn the faithful to hold fast to the traditions which they have learned either by word of mouth or by letter (see 2 Thess. 2:15), and to fight in defense of the faith handed on once and for all (see Jude 1:3) (cf. Second Council of Nicea: Denzinger 303 (602); Fourth Council of Constance, session X, Canon 1: Denzinger 336 (650-652).) Now what was handed on by the Apostles includes everything which contributes toward the holiness of life and increase in faith of the peoples of God; and so the Church, in her teaching, life and worship, perpetuates and hands on to all generations all that she herself is, all that she believes.
A few important concepts:
We have a presumption that faith precedes intellect; the tradition of the Apostles builds on faith; it doesn’t (necessarily) provide its foundation.
Teaching is only one aspect of the handing down of God’s Word; worship is another.
The allusion to the “life” of the Church seems unclear at first. I believe it refers to caritas et amor, the lived example of Christians, especially the love they express to one another (community) and the love for the needy (justice and charity).
This tradition which comes from the Apostles develop in the Church with the help of the Holy Spirit. (cf. First Vatican Council, Dogmatic Constitution on the Catholic Faith, Chap. 4, “On Faith and Reason:” Denzinger 1800 (3020).) For there is a growth in the understanding of the realities and the words which have been handed down. This happens through the contemplation and study made by believers, who treasure these things in their hearts (see Luke, 2:19, 51) through a penetrating understanding of the spiritual realities which they experience, and through the preaching of those who have received through episcopal succession the sure gift of truth. For as the centuries succeed one another, the Church constantly moves forward toward the fullness of divine truth until the words of God reach their complete fulfillment in her.
Note the threefold path in which a believer grows:
Not just study, but an integration of contemplation with intellectual learning.
Putting personal experience through a lens of a deep spiritual sensibility.
Preaching not just in an apostolic tradition, from the episcopal tradition, namely that of shepherd for flock.
Also note a whiff of progressive optimism, namely that the Church moves forward in insight and understanding as the experience of centuries of God’s grace adds to what is already God’s gift.
Dei Verbum 8 strikes me as an acknowledgement that Tradition is far beyond scholarship. It naturally incorporates liturgy as a means of passing on tradition and as a way to holiness for the baptized. It recognizes that active life (caritas et amor) is integral to the experience of grace in revelation. Revelation is also more than a passive reception of grace; this final portion speaks of a conversation between God and the Church.