The Rosary Light & Life - Vol 47, No 3, May-June 1994

Theology for the Laity


By Father Paul A. Duffner, O.P.

One of the first things that a Catholic mother teaches her young child in the way of prayer is the sign of the cross. She shows the young one how to bless himself, while at the same time pronouncing the names of the three divine Persons of the Blessed Trinity. While the child at that age may understand little of the words pronounced, there will come in time a gradual awareness of this great mystery of our faith; for throughout one's life as a Catholic there will be frequent references in prayer, in the reception of the sacraments and in the liturgy to the Blessed Trinity.

The mystery of the Trinity is the very foundation of our Catholic faith. The Apostles' Creed is simply a brief expression of our faith in the three divine Persons. The history of our salvation rests upon the mystery of the Trinity. For God the FATHER sent His only-begotten Son into the world to redeem us. The SON gave his life in accomplishing that work of redemption; and the HOLY SPIRIT brings about the sanctification of each individual soul, by applying to the soul the graces merited by Christ's redeeming sacrifice. Our Christian life began when we were baptized in the name of those three divine Persons.


While we presume to write about the divine Trinity, we must confess that we are dealing with a mystery that no human or angelic mind can comprehend. Even St. Paul, who "was caught up to third heaven... and heard secret words that no man can repeat" (2 Cor.12:2) declared: "O the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable are his ways" (Rom.11:33). Because of the vastness of this topic, these reflections can be only the barest outline.

By the light of reason alone man can arrive at the knowledge of the existence of a supreme being who is responsible for the order in the universe; but he could never arrive at a knowledge that in the one true God there are three Persons. And even after Christ revealed it, it is still for us an incomprehensible mystery. We believe this truth because God has revealed it to us. But to understand how it is so, we will have to await God's fuller revelation of Himself in the life to come. Nevertheless, the first Vatican Council assures us that human reason illumined by faith, can attain with God's help some fruitful understanding of this supernatural mystery.

A comparison between the human and the divine might shed some light on our enquiry. James, John and Peter are three distinct persons. Each one is endowed with his own human nature. Each one thinks and wills with his own individual intellect and will. James doesn't think with Peter's intellect, nor does James choose or command with John's will. They are three human persons with three distinct human natures, each with his own individual faculty of knowing and willing.

In the divine Trinity, however, while there are three distinct Persons, there is only one divine nature. The inner life of God is that of infinite knowledge and love. God knows infinitely, and loves infinitely; but all three divine Persons know and love with one and the same divine mind and divine will. And, as we shall see, from that infinite inner life of knowing and loving there issues the relationships on which the distinction between the divine Persons is based.

NOTE: Lest this be a source of confusion as regards Christ, the Redeemer, He is a divine Person having two natures, one divine and one human. It was His human will submitting to the divine will when He said: "Father, not my will, but yours be done" (Lk. 22:42).


A) Old Testament: The Old Testament does contain allusions to the Trinity, but they are so vague that before the coming of Christ no one was aware of their meaning. For example, the plurality of persons is implied in Genesis: "Let Us make man in Our image and likeness" (1:19). "Let Us then go down and there confuse their language" (11:17). And in the triple invocation Isaiah heard the Seraphim cry: "Holy, Holy, Holy, the Lord God of Hosts, all the earth is full of His glory" (6:3).

B) New Testament:

  1. Message of Archangel Gabriel: "The Holy Spirit will come upon you and the power of the Most High will overshadow you; hence, the holy offspring to be born will be called Son of God" (Lk.1:35).
  2. At the baptism of Jesus: "After Jesus was baptized, he came directly out of the water. Suddenly the sky opened and he saw the Spirit of God descend like a dove and hover over him. With that, a voice from heaven (the Father's) said: 'This is my beloved Son. My favor rests on him' " (Mt.3:16).
  3. At the Last Supper: "The Paraclete, the Holy Spirit whom the Father will send in my name, will instruct you in everything, and remind you of all that I told you" (Jn. 14:26).
  4. Before the Ascension: "Go, therefore, and make disciples of all nations. Baptize them in the name of the Father, and of the Son, and of the Holy Spirit" (Mt. 28:19).

Since our faith tells us that there are three divine Persons in God, and since God had no beginning, the question comes to mind: why precisely three Persons, and what is the relationship between them? The Scriptures speak of the Father as the creator and source of all things. But he could not have created the Son and the Holy Spirit, otherwise they would be creatures, and not God. We know from our faith that they are divine Persons co-equal and co-eternal with the Father.

We find the answer to the origin of the Son and the Holy Spirit in the Church's teaching that in God there are two internal divine processions. The word procession is used here to mean the origin of one from another . . . one proceeding from another. And we speak of "internal" processions - referring to the inner life of God, as opposed to "external" procession, which refers to God's action in regard to creatures. Both the SON and the HOLY SPIRIT proceed from an imminent act of the Holy Trinity, i.e. from an internal divine procession by which one divine Person originates from another communicating totally one and the same divine essence. We shall see, however, that the manner of origin of the SON differs from that of the HOLY SPIRIT, because of the two diverse internal Processions in God. For example:

  1. The origin of the SON is by way of generation. The Father begetting the Son by an eternal act of contemplating his own divine essence.
  2. The origin of the HOLY SPIRIT is by way of spiration. From the mutual and infinitely ardent mutual love of the Father and the Son there issues forth as from a single source a living FLAME OF LOVE which is a divine Person, the Holy Spirit, sharing perfectly in every way the divine nature of the Father and the Son. We will consider a bit more in detail these two internal processions that constitute the inner life of God.

When we speak of Father and Son in God, we have to keep in mind that God is a pure spirit, having no body. Consequently we must be careful not to confuse generation in God with the use of that term in regard to human generation. But even in human language we speak of conception as a mental process as well as physical. A woman conceives a child . . . and any adult can conceive an idea. "Who conceived that brilliant idea?" someone might ask.

It is in this spiritual sense that we speak of begetting in God. God the Father, whose knowledge and capacity of knowing is infinite, contemplates eternally His own divine being, His own divine essence. The IDEA or IMAGE or MENTAL WORD conceived of Himself in His own divine mind is an absolutely perfect living representation of the Father. This living image of Himself which the Father has been begetting from all eternity is a divine Person distinct from the Father. Sharing one and the same divine nature as the Father, He is the Father's only-begotten Son. As St. Paul expressed it: "This Son is the reflection of the Father's glory, the exact representation of the Father's being" (Heb.1:3).


We have no problem forming a mental image of the SON who became man, for many details of His life have been recorded for us. And we can in a vague way have a mental image in our imagination of the Father of whom our Blessed Lord spoke many times, and whose voice was heard at the baptism and transfiguration of His divine Son. But the images that the Scriptures give us of the Holy Spirit are only that of a dove at the baptism of our Lord, and of tongues of fire at Pentecost. Yet, the Holy Spirit is a divine Person distinct from the Father and Son, and sharing perfectly their divine nature.

The inner life of God is not only one of infinite knowledge from which comes forth the WORD BEGOTTEN, but one of infinite love from which comes forth the HOLY SPIRIT. Because the SON possesses the infinite perfection of goodness, knowledge, holiness, beauty and power of the Father, both divine Persons behold the infinite lovableness of each other. Yet, it is the function of love to reach out for what is lovable, and to give oneself without reserve to the one loved. There is a reflection of this in human love. However, the love of the FATHER for the SON, and of the SON for the FATHER is so perfect, and so complete is their giving of self, that there issues forth an infinite expression of this love in a living Person, co-eternal and co-equal with the Father and the Son. The Scriptures call this third divine Person the Holy Spirit because He is "breathed forth" by the love of the Father and the Son. As the Roman Catechism expresses it, the Holy-Spirit "proceeds from the divine will inflamed, as it were, with love."


So far we have been considering the interior activities, or the inner life, of the three divine Persons. The exterior activities of the Trinity are those, the term of which is outside of God, i.e. those that affect creatures. It is the teaching of the Church that all exterior activities of God are common to the three divine Persons. Any act of God on the created world is an act of the three divine Persons acting as a single principle. As St. Thomas explains, "to produce any effect in creatures is common to the whole Trinity, by reason of the oneness of their nature; since where there is one nature there must be one power and one operation" (III,23,3).

The external works of the Blessed Trinity are usually classified under three categories: the work of creation, of redemption and of sanctification. And even though, as we have just seen, all three divine Persons share in all of these external works, the Scriptures attribute the work of creation to the Father, of redemption to the Son, and of sanctification to the Holy Spirit. The attributing to individual divine Persons activities and qualities that pertain to all three Persons is referred to by theologians as APPROPRIATION. This is done to help clarify in our minds the distinction of the divine Persons themselves, and to shed some meager light on this unfathomable mystery. With this in view we will consider briefly each of the divine Persons.


Since the Father does not proceed from any other source, we think of Him as the origin of all things, as one of great power in producing all that exists. So the quality of omnipotence is attributed to Him. Thus the Church refers to Him in the Apostles' Creed as "the Father almighty, Creator of heaven and earth."

To the Father is attributed the wonderful Providence with which God cares for all that He has created, and especially for man made to His image and likeness. "Your Providence, Father, pilots all things" (Wis. 14:3). "Do not be anxious . . . your Father knows that you need all these things" (Mt.7:32). "Our Father who art in heaven. . . . Give us this day. . ." (Mt. 6:9).


Since the Son proceeds from the Father by way of knowledge as the perfect Image of the Father, there is attributed to the Son truth, wisdom and the order of the universe. Both His life and teaching are an expression of divine wisdom which, to the world, often appears as foolishness. "I am the Way, the Truth and the Life" (Jn. 14:6).

However, the human nature assumed in the Incarnation of the Word is not an appropriation. The second Person of the Trinity did assume human nature, and the Father and the Holy Spirit did not. Yet every act of the God-man, who is a divine Person, proceeds from divine omnipotence under the direction of divine wisdom and inspired by divine love, all of which are common to the three divine Persons acting as a single principle.


Because the Holy Spirit proceeds from the mutual love of the Father and the Son, works that are an expression of God's love are attributed to the Holy Spirit. Thus everything that contributes to our sanctification, every outpouring of divine grace, is attributed to the Holy Spirit. "The charity of God is poured forth into our hearts by the Holy Spirit who has been given to us" (Rom. 5:5).

It is clear from the Scriptures that God wishes us to use the appropriation of certain works to individual Persons of the Trinity to help clarify the distinctive characteristics of each of the three divine Persons. Our Lord Himself frequently spoke in such terms. Yet, as we have pointed out, although we attribute works of power, wisdom and love to different divine Persons, everything that happens in the world does so by the power, wisdom and love of all three divine Persons. Even the evil that befalls us is permitted by God's love, because in His infinite wisdom He can bring good out of evil.


In God's care for the world His infinite power, wisdom and love are inseparable. Nothing happens in this world that is not brought about or allowed by the will of God, i.e. of the three divine Persons. If we live by our faith and trust in the Holy Trinity, we will remember that God permits only what is for our ultimate good. How could it be otherwise when infinite wisdom directs and infinite love inspires all that is brought about or permitted by God's almighty power?

Our life is so intimately bound up with this greatest of mysteries, that it is of great importance that we realize its impact on our whole existence. God has made known this great mystery to us that we might have unfailing hope throughout life. No matter what befalls us, God can bring good out of every situation because His power, directed by His wisdom and love, is ordering the course of our life.

What a comfort it should be in times of distress, when the future looks bleak, when temptation increases, when sickness or injury is our lot, to know that we are sustained by the wisdom, love and power of God Himself. But this peace of mind and heart presupposes a deep faith that makes us aware of these truths, a trust that never doubts that God knows best, and a love that always says "yes" to God's dealing with us.

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