The Final Steps on Our Spiritual Journey Part III: The Path of Union

By Fr. Ambrose Sigman, O.P. Light & Life Newsletter, V75n2, March-April 2022


The Final Steps on Our Spiritual Journey Part III: The Path of Union

By Fr. Ambrose Sigman, O.P.

We end now with the final stage of the spiritual life, the summit of the mountaintop. If we recall the story we began with, the story of the Transfiguration, what was it that greeted the apostles on top of Mount Tabor? A vision of Christ in glory, as well as a vision of the Trinity, revealed in the Cloud, the Voice from heaven, and the Son of God shining forth with the divine light. This is what each of us is aiming for when we embark upon the spiritual path toward perfection; this is what awaits us when we reach the summit. By God’s grace, we can be made worthy to behold this vision. 

Much of this final stage is not for this life; we will never know the fullness of spiritual joy as long as we still live, burdened as we are by the weaknesses of this fallen world. We will not come into the fullness of this vision of God until the consummation of all things. But, as all the great spiritual writers acknowledge, it is possible while still in this world to be given a foretaste of this ultimate end, to be allowed a small taste of the spiritual joys which are in store for us, if for only brief and fleeting moments. In addition to this, there is also something to be said for having a clearer idea of our own end, of what it is we are aiming for. Not only does this make the journey easier (we can see where we are going), it also gives us something to aim for, and in which to have hope. We are better off when we have a clear idea of where we are trying  to go.

Natural Love

We can now examine with more detail what this final stage looks like, and how we can begin to approach it. To begin with, we must first talk about love, because this is what ultimately lies at the heart of the union between human beings and God. It is, in conjunction with prayer, what brings that union about. As we cleanse ourselves from the passions, there occurs in us the first stages of growth in the love of God. The love of God begins to trickle into the soul and strengthens it in the quiet of its dispassion. As this process continues, more and more it is the divine love, or the Holy Spirit, which comes to work in us. This love, then, is the opposite of the selfishness of the passions. The great Greek spiritual author St. Diadochus of Photiki wrote the following: 

“He who loves himself, cannot love God. But he who does not love himself because of the overwhelming richness of the love of God, loves God, for such a person never seeks his own glory, but that of God. Because he who loves himself seeks his own glory, but he who loves God, loves the glory of Him who made him. Since it is proper to the sensitive soul to always seek first the glory of God in all the commandments which he is carrying out, and secondly, to enjoy himself in his humility” (On Spiritual Knowledge 12).

Because this growth in love goes hand in hand with our spiritual development, we can trace out the steps in this path of love. The first step is the tendency of the natural sympathies born from the state of nature fallen from grace. This is what you might call natural love, the love which is simply the force of desire, the force which attracts us to natural needs, like food and drink, and the force which attracts us to material pleasures or any other thing or person that we perceive as a good for us. St. Thomas Aquinas, for example, classifies these kinds of desires under a broad definition of love.

Christian Love

The second step is more properly Christian love. This love makes use of the preceding tendency and grows by divine grace and individual efforts; it brings nature to a kind of fulfillment. As this love progresses it becomes stronger and more stable, it is strengthened as it approaches that kind of love called in the tradition “ecstasy,” a gift which comes to us exclusively from God. This second love prepares the soul for this gift. This gift of ecstatic love is the third and final step.  This comes after a long preparation through the second step and lasts only for moments. In the second step, the human person is raised to the fullness of his nature, aided by grace. This final gift raises the human person above the limits of nature. 

Love grows in us according to the measure of its exercise and of the will to intensify it. In the measure in which we open our heart to others, we enlarge it for the ocean of divine love. This unending divine love overwhelms us and an infinite impulse to embrace everyone floods us, this is the gift of ecstatic love. St. John Climacus writes, “Love by quality is likeness with God, in so far as is possible for mortals. By energy it is intoxication of the soul. By attribute it is the fountain of faith, an abyss of longsuffering, a sea of humility” (Ladder of Divine Ascent 30.7). The Fathers referred to this kind of love as bringing a “sober intoxication.” We, in a sense, become drunk on the spiritual drink which is love. St. Isaac of Nineveh writes the following, “the Apostles and martyrs, long ago, became drunk with this spiritual drink; the first, traveling all over the world in toils and in shame, the latter having their limbs cut off, shed their blood like water; and suffering the worst things they did not weaken, but bore it all.”

Divine love floods with its enthusiasm the worldly judgment of the mind and the feeling of the body. We see another world, a different state of being, a different way of looking at the world, we think according to a different logic. So, to the world around us, the saints and martyrs, possessed by this love, seemed foolish, but they are the truly wise. By loving a loved one, we are transformed; this is true with any human love. How much more is it true when our beloved is God Himself? Again St. John Climacus, “If the face of the one we love clearly and completely changes us and makes us radiant and content and happy, what will the Lord’s face invisibly do when He comes to the pure soul?” (Ladder 30.19).

Human beings seek ultimately to be united to God, this union is the culmination of the spiritual life, it is its purpose and end. As has already been alluded to, this union is brought about through love. To understand better how love serves as the source of this union we must look more closely at the nature of love itself, and how love can serve this function. For this we turn to the works of Saint Thomas Aquinas. 

Union of Similitude

When speaking about love in terms of human relationships, or what we might call natural love, Aquinas identifies three types of union: the union of similitude, the union of affection, and the union of possession. The first kind of union (of similitude) precedes love. The union of similitude is the fittingness or compatibility of one thing for another, without which love is not possible. Nevertheless, Aquinas does not define love as a union of similitude, for the passion of love (as, likewise, freely chosen love) designates a change in the lover towards what he loves. 

Union of Affection

Love is itself a union of affection in which one being takes another as its good and therefore either desires union with it or delights in a union already possessed with it. The affective union that is love ‘enables’ that particular good which is loved to act as an end or final cause with respect to the lover. This love, then, can be with either what is had or not had, though the aim of love is to have that good, which leads to the third form of union. 

Union of Possession

Love impels, through desire, toward the third union (of possession), in which it rests, by delight. When the loved good is absent, desire emerges; by it the lover tends toward this union [of possession]. If the loved good is present, the lover rests in this union through delight. The distinction between union of affection and union of possession opens up the ‘space’ for desire’s striving. This union of possession is the final end and goal of love. From the initial inclination of love, through the movement of desire, the rest of delight, all love tends toward an actual union with the beloved. This will help us to better understand that ultimate union rational creatures hope to achieve with God, through the love Aquinas calls charity (caritas).

The “Vertical” Dimension of Charity

Now we see the general process of how human beings love in a natural way. Love is ultimately the force which unites lover with the beloved, be it between us and an object of our desire, or between persons. This helps us, then, to better understand our relationship of love with God through charity. For Aquinas, charity is defined as God’s friendship with human beings. He writes in the Summa Theologiae (ST, II-II, 23.1; cf. 1Cor1:9), “Now there is a sharing of man with God by his sharing his happiness with us, and it is on this that a friendship is based. St. Paul refers to it, 'God is faithful, by whom you were called into the fellowship of his Son.' Now the love which is based on this sort of fellowship is charity. Accordingly, it is clear that charity is a friendship of man and God.” The key to St. Thomas’ position on the nature of charity lies in this teaching: the one thing which can make us completely happy is the life and happiness of God Himself. 

It is from this sharing that the love of friendship called charity flows. In his article on charity as friendship (“Charity as Friendship in the Theology of Saint Thomas,” Angelicum 52 (1975): 170), Louis Hughes, OP, writes the following,  "Returning to 1 Corinthians 1:9, St. Thomas concludes from this text that God in calling us to fellowship with himself, is really sharing with us his own divine happiness. The friendship which must arise from this sharing can only be charity. The  virtue of charity is thus seen to be friendship between God and man, based on a sharing in the divine happiness. This is charity in its primary meaning, what might be called its ‘vertical dimension.” This “vertical dimension” is one aspect of charity, the love between God and man. The other, or what Hughes calls the “horizontal dimension,” is charity as man’s love for his neighbor.

The “Horizontal” Dimension of Charity

This secondary aspect of charity, the person’s love for their neighbor, stems from the love man has for God. Aquinas writes, “Now the light in which we must love our neighbor is God, for what we ought to love in him is that he be in God. Hence it is clear that it is specifically the same act which loves God and loves neighbor. And on this account charity extends not merely to the love of God, but also to the love of neighbor” (ST II-II, 25.1). The good shared between two graced persons is the same good that each one shares with God. It follows, then, that the charity with which they love God and each other is of the same species of love.

Aquinas lays out for us a clear understanding of the nature of love, and we can begin to see how love, namely the love of God, is the source of the union between the human and the divine, a union which does not meld the two things together but creates ever deeper bonds of intimacy while allowing the subjects to remain intact. This love which comes from our encounter with God is also a kind of rediscovery on our parts. Human nature, being the work of the creative love of God, finds itself in a relationship and in an original nearness to Him. The union realized by love gives it the sentiment of rediscovery, of coming home again, of entering into rest, the delight we discussed earlier. It is as Saint Augustine said, “My heart is restless, O God, until it rests in Thee.” We have the feeling that in the love of God as ecstasy, God has opened His heart to us and received us into it, just as we have opened our heart so that He can enter in.

Having seen how this union is achieved through love, we move on now to speculate about the nature of this union itself, what it means to us, and what it does to us. For this we return to the story of the Transfiguration. In this story, what  greeted the apostles at the top of the mountain? It was Jesus Christ, transfigured and shining with an uncreated light. The vision of this divine light, the light of Tabor, has been used by a great many spiritual authors to describe our ultimate union with God. Human beings, at the end, are granted a vision of this divine light, a vision of God in glory. This plays into what Aquinas talks about when he discusses the beatific vision. But what is this light? What does it mean? Let us look at how various authors have discussed and interpreted it.

The Light of Divine Love

St. Irenaeus of Lyons speaks about the “Paternal Light” of the Father, revealed in the Light of Tabor, which gives men a foretaste of the life of the world to come, when we will all shine with such brightness. St Basil the Great said that the light is a revelation of the splendor of Christ, and thus of His glory. This light is the intelligible manifestation of Christ’s divine glory, and it is contemplated through the mind, heart, and soul (Homily on Ps. 25). St. Gregory of Nazianzus tells us that Christ’s divinity was revealed as light through His human form. This light is reflected throughout the history of salvation: the Burning Bush, the Pillar of Fire which guided the Israelites in the wilderness, the light of Moses’ face, Elijah’s  chariot of fire, and the light the Shepherds saw at Christ’s birth, the Star of Bethlehem (On Holy Baptism, Oration 40).  Finally, St. Maximus the Confessor identified the light with the Divinity of Christ, one perceptible to men (hence the  apostles), and yet which remains a mystery, incomprehensible to a created human intellect. This incomprehensibility resides in the mystery of the Divinity as both one and three. The Light of Christ is the triune light of the Holy Trinity. Hence the Transfiguration Light is a Trinitarian revelation (Ambiguum 10). This, of course, is but a small sample of the writings of the Fathers on this subject.

As you can see the light of Tabor can have a great many different, and yet complementary, meanings. Seeing by the light of the divine love which proceeds from God, and which is reflected in the mind itself – this light fills the mind and makes it light. Whoever looks at a light which is shining from the face of a loved one is also filled with this same light. The light and brilliance from the face of the beloved also reaches the face of the one who loves and envelops both in a common light and joy. In time, this imprints them with common values and traits and makes the two alike. The one who has purified him or herself of the passions and has reached a burning love for God through the practice of the virtues can attain a vision of the divine light, like the apostles on Tabor. This means that they have spiritualized their nature to such an extent that this nature itself has become warmth and a light of the love of God and of men. This person no longer has in himself any coldness or shadow of care for himself. This state is the result of his own efforts and of the aid of the Holy Spirit. 

This vision of the divine light, granted to those who grow ever deeper in love, begins to conform us ever more to God Himself. We begin a journey of becoming more and more godlike. The vision of the light begins to transform us into the light, and the more we love the beloved, God, the more like the beloved we become. We literally start to become godlike. This is the promise of 2 Peter 1:4. We are, of course, not a god by nature, but we become like God by grace. 


This process is the culmination of the spiritual life, and it has been called by various names. In the Greek East, it is referred to as theosis, deification or divinization. Saint Athanasius of Alexandria, in describing the Incarnation of Christ, wrote, “God became man in order that man might become like God.” This can also be seen in the discussion of Saint Thomas Aquinas on the beatific vision. This is the ultimate end of the human person, the goal of the spiritual life, to grow into an ever-increasing likeness to God Himself, made possible for us by the Incarnation. 

This process of deification has two aspects to it. First, through this process, human nature becomes fully actualized.  Deification is God’s perfect and full penetration of the human person. Sin has dulled and chained up the powers of human nature. We do not know the full scope of the powers which our nature is capable of. Envy, anxiety, and hate have clipped its wings. This process of love grants our nature the wings to fly again. 

The first step of deification then is the restoration of human nature to its original potential, a potential diminished by sin and the Fall. This restoration is brought about by cooperation with divine grace. This part of the process of deification, then, begins at Baptism, and stretches across the whole of the person’s spiritual ascent. In this ascent the natural powers of the person are in continual growth and reach their apogee the moment they become capable of seeing the divine light, through the aid of the Holy Spirit. We can say, then, that the deification by which this revival and growth is realized coincides with the process of the development of human powers to their limit, or with the full realization of human nature.

But the process does not end there; in fact, the process never ends. Deification never stops. Our human powers are unendingly eclipsed by grace; we are placed on an infinite path toward an ever greater conformity to God. This, then, is the second part of the process, the continual and unending growth in the divine life, and this part is entirely a gift of God’s grace. There is here no activity on our part, we have spent our spiritual lives learning to make of ourselves receptacles of God’s love, and having achieved this, we receive into ourselves the very life of God as a gift from on high. As God Himself is infinite, it is possible to grow infinitely in love of Him and in conformity to Him. This is what Jesus prays for in the so-called “high priestly prayer” from the Gospel of John (17:1-26), this is the beatific vision which Aquinas talked about, and this is the goal toward which our spiritual lives aim.

Note from the Director

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Ecce Homo - Philippe de Champaigne (1602–1674)


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