The Trinitarian Christology of St. Thomas Aquinas | Fr. Dominic Legge, OP

(Oxford: Oxford University Press, 2017), 24-25, 48, 54-55.

When we read the New Testament, we cannot miss the visible missions: the Father sends the Son into the world as man; the Holy Spirit descends on Jesus in the form of a dove, and on the Apostles in tongues of flame.  But invisible missions are clearly mentioned, too: “God has sent the Spirit of his Son into our hearts, crying, "Abba! Father! (Gal. 4:6).” . . . .

The term “invisible mission” refers to the sending of a divine person to a human being (or an angel) “through invisible grace,” and it “signifies a new mode of that person’s indwelling, and his origin from another.” Both the Son and the Holy Spirit are sent invisibly “since it befits both the Son and the Holy Spirit to indwell through grace and to be from another;” although the Father also dwells in human beings “through grace,” he is never “sent” because he is not “from another.”  An invisible mission thus has the two elements that characterize every divine mission: an eternal procession of a divine person from another, and a created effect by which that procession is made present in a new way in a creature.

These missions are called “invisible” because “the indwelling by grace,” is a spiritual reality in the soul that cannot be seen directly. Aquinas underlines that this new presence can only be according to sanctifying or habitual grace – and, more specifically, that it is according to the gifts of wisdom and charity that a creature receives in sanctifying grace.  These are created effects given to the creature, but – this point is capital – in these created effects, the divine persons are sent in person and really begin to dwell in the creature: the Son in wisdom, and the Holy Spirit in charity.

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When Aquinas speaks of the “visible missions,” he is designating the incarnation of the Son, the visible manifestations of the Holy Spirit as resting on Christ (at Christ’s baptism and at his transfiguration), and the visible outpouring of the Holy Spirit on the Blessed Virgin Mary and the Apostles after the resurrection (Christ breathes on them on the evening of the resurrection, and then tongues of fire descend on them at Pentecost).

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The visible missions are therefore (1) a revelation of the divine persons, making known the invisible things of God, and (2) the historical events at the center of the economy of grace (since all grace comes to us through, and in virtue of, Christ’s incarnation).  These dimensions are interrelated: the visible missions manifest the mystery of the Triune God, and save us as they draw us into that mystery.  This double aspect of manifestation and salvation is a fundamental trait of the entire dispensation of salvation. 

More specifically, the manifestations are for the sake of our salvation: the visible missions are ultimately ordered to the invisible missions.  In one of his sermons, Aquinas puts this rather bluntly: the Son’s visible mission as man “leads to another coming of Christ, which is into the mind.  It would have been worth nothing to us if Christ had come in the flesh unless, along with this, he would come into the mind, namely, by sanctifying us.” (St. Thomas Aquinas, Sermon Ecce rex tuus.)