Gaudium et Spes continues a discussion of the relationship between culture and the Gospel. First the importance of perceiving the needs of particular cultures, and two reasons are given: the effectiveness of kerygma, but also the enrichment of the church’s leitourgia:
There are many ties between the message of salvation and human culture. For God, revealing Himself to His people to the extent of a full manifestation of Himself in His Incarnate Son, has spoken according to the culture proper to each epoch. Likewise the Church, living in various circumstances in the course of time, has used the discoveries of different cultures so that in her preaching she might spread and explain the message of Christ to all nations, that she might examine it and more deeply understand it, that she might give it better expression in liturgical celebration and in the varied life of the community of the faithful.
The Church’s interface with human cultures is essentially a pragmatic one:
But at the same time, the Church, sent to all peoples of every time and place, is not bound exclusively and indissolubly to any race or nation, any particular way of life or any customary way of life recent or ancient. Faithful to her own tradition and at the same time conscious of her universal mission, she can enter into communion with the various civilizations, to their enrichment and the enrichment of the Church herself.
Note the mention again of liturgy at the end:
The Gospel of Christ constantly renews the life and culture of fallen (humanity), it combats and removes the errors and evils resulting from the permanent allurement of sin. It never ceases to purify and elevate the morality of peoples. By riches coming from above, it makes fruitful, as it were from within, the spiritual qualities and traditions of every people and of every age. It strengthens, perfects and restores (6. Cf. Eph. 1:10.) them in Christ. Thus the Church, in the very fulfillment of her own function, (cf. the words of Pius XI to Father M. D. Roland-Gosselin “It is necessary never to lose sight of the fact that the objective of the Church is to evangelize, not to civilize. If it civilizes, it is for the sake of evangelization.” (Semaines sociales de France, Versailles, 1936, pp. 461-462).) ) stimulates and advances human and civic culture; by her action, also by her liturgy, she leads them toward interior liberty.
My eyes can’t help but perk up at the mention of liturgy in any of the conciliar documents. Here’s a somewhat surprising insight: liturgy as an agent for interior liberty.