In theory, the Liturgy expresses the will of Christ:
55. Any unilateral exaltation of popular piety which fails to take account of the Liturgy, is inconsistent with the fact that the essential elements of the Liturgy derive from the will of Christ himself, and is unable to emphasize its indispensable soteriological and doxological importance.
It is the Paschal Mystery which should lodge deepest in the heart of a believer. Each believer is called to “participate” in this event:
Following the Lord’s ascension to the glory of the Father, and the descent of the Holy Spirit, the perfect glorification of God and the salvation of (humankind) comes about primarily through the celebration of the liturgy (Cf. SC 5-7), which requires an adherence of faith, and brings the believer to participate in the fundamental salvific event: the Passion, Death and Resurrection of Christ (cf. Rm 6,2-6, 1 Cor 11,23-26).
What does this mean, this participation? I would venture to say it goes beyond the participation in the salvific actions of Christ in the liturgy. Though it certainly includes being baptized and the regular reception of the Eucharist, believers are also called to the imitation of Christ. The liturgy provides the inspiration for that, in part. We hear the Word, and we receive nourishment, and so we are both inspired and strengthened to do as Christ would do.
If we are living the example of Christ, then the devotional life will be centered on that.
The Church’s understanding of her mystery, and her worshipping and saving actions, constantly affirms that it is through “the Liturgy…, especially in the divine sacrifice of the Eucharist, [that] ‘the work of our redemption is accomplished'”(SC 2). This affirmation, however, does not deny the importance of other forms of piety.
So if we are living the salvific reality, our acts and practices of piety are not in conflict with the root of the mystery of Jesus Christ.
The full document, the Directory on Popular Piety and the Liturgy, is online at the Vatican site.
Catholic Sensibility 