1. Once the sacraments’ essential character as cooperative acts is clear, one can proceed to clarify several other aspects of their complex reality. For instance, as outward performances, they have a symbolic dimension which will no longer be necessary in heaven (so that, like faith and hope, they will be surpassed).
The sacraments also involve something permanent, insofar as they restore and perfect fallen human persons. Thus, baptism, confirmation, and orders give a permanent character. Penance gives reconciliation, which in principle is meant to last. Anointing prepares the body for resurrection. The Eucharist and matrimony establish loving interpersonal communion which is a beginning of heavenly fulfillment. In all the sacraments, furthermore, we are united with Jesus, drawn from our present unstable situation into his present and lasting glory.
2. Defining the sacraments as signs emphasizes their transient, symbolic dimension, which belongs to them as outward performances. This dimension is generally and correctly said to be important because we humans are bodily and learn by experience, and because the tremendous realities involved in the sacraments would be too great for us without the mediation of symbolism. Therefore, it is said, God kindly provides a simple, sensible sign suited to our condition (see S.t., 3, q. 60, a. 4; q. 61, a. 1).
3. Though perfectly true, this ought not to be misunderstood. As Trent teaches, the sacraments are more than signs of faith; they really contain and confer the grace which they signify. Like the glorified Jesus, whose acts they are, the sacraments are complex realities, and their bodily dimension is not what is most important about them. At the same time, this bodily, symbolic dimension is not a mere means, something extrinsic to their sacred reality. Rather, like the body of Jesus in glory, it is an essential part of the sacraments’ redeeming and sanctifying power.
4. One might imagine the work of sanctification as occurring through the soul’s purely spiritual and interior communion with God. This in fact is how Protestants faithful to the theology of the Reformation do think of it. The difficulty is that this excludes any social act. Human beings are in communion only by way of bodily cooperation. Unless they do something together as an outward performance—at least something symbolic like uttering words and making gestures—they cannot do anything together which is a human act. Eliminating the sacraments thus eliminates the possibility of effective cooperation between our Lord in glory and human beings joined with one another (see S.t., 3, q. 62, aa. 1–2).6
5. The outward, symbolic dimension of the sacraments is best understood in light of their essential reality as cooperative divine-human acts. Human beings wish to contribute to their own salvation; they wish to do something to be saved. In the sacraments, God makes this possible. Having effected redemption in principle by the Incarnation of the Word, where creation, represented by the humanity of Jesus, cooperates in its own re-creation, God carries redemption through to completion in the sacraments. In these divine-human acts created and fallen persons collaborate with Jesus in their own reconciliation and sanctification.
6. Considering the sacraments as signs, one might paraphrase and expand a familiar definition as follows: A sacrament is a meaningful performance instituted by Jesus to communicate the fruits of his redemptive act to human persons, so that they will receive these fruits as gifts in whose receiving (for themselves) and giving (to others) they can consciously and freely cooperate.
Another analogy might be helpful, one more complex than that of the mother making bread, since both the divine-human cooperation and the symbolic aspect of the sacrament are represented.
Imagine an operating room. A man is undergoing surgery; his blood is being circulated by a heart-lung machine concealed behind a one-way mirror; and he is conscious, since the anesthetic blocks pain only. He has been told to blink his eyes when he begins to feel weakened. When he does so, an attendant who is facing the mirror grimaces. The person in control of the heart-lung machine which is sustaining life then adds a nutrient to the bloodstream. To do this, however, the nutrient must be provided. Some source outside the hospital is responsible for this.
The patient is like the recipient of the sacrament. The attendant who is authorized to signal for more nutrient is like the minister of the sacrament. The person operating the heart-lung machine is like Jesus, who now lives beyond the veil, but still acts to sustain our lives (see Heb 6.19–20). Finally, the source of the nutrient is God. Of course, he also is the source of all the other elements.
6. See Josef Jungmann, S.J., The Liturgy of the Word, trans. H. W. Winstone (Collegeville, Minn.: Liturgical Press, 1966), 7.