The clergy must preach the Word, although the sermon is not the form of the Word of God, it is only the way in which it is mediated. The Gospel is not at the service of preaching, nor is it just a rich source of quotations for the orator in the pulpit. The sermon’s purpose is one of introduction to the Gospel, to its essence.
The same is true for the catechism and for all the other means of Christian instruction... The same is true at another level for the liturgy as a whole and in its single elements. However important it is for the Christian people to celebrate in a worthy manner the memorial of the passion of Christ, it is equally essential... that the people, through all these ceremonies, immediately see their meaning and their reality, and never see the ceremonial part, however beautiful and worthy it is, as an end in itself.
Hans Urs von Balthasar
Sponsa Verbi, Esistenza Sacerdotale
Morcelliana, Brescia 1985, p. 403