At the end of this journey in faith and thought, all that is left for us to say is a Biblical Amen. Amen is a Hebrew expression of assent deriving from amin, which means believing in, accepting and handing oneself over to God and God’s plan. Amen is humankind’s response to the revelation of the triune God: So be it! How good that it should be so! Come, most holy Trinity, come! It is pronounced in an atmosphere of worship and reverence for the unspeakable mystery. But before finally praying Amen and falling respectfully silent in the face of the august Trinity, let us give reason one last turn, in an attempt to sum up in a number of propositions the basis of the Trinitarian doctrine developed above:
1. By “God” in the Christian faith we should understand the Father, the Son, and the Holy Spirit in communion with each other, in such a way that they form a one and only God.
2. In relation to the Trinity, doxology precedes theology. First we profess faith in Father, Son, and Holy Spirit in prayer and praise (doxology). Then we reflect on how the divine Three are one single God in perichoretic communion between themselves (theology).
3. In theological reflection, the economic Trinity precedes the immanent Trinity. By “economic Trinity” we mean the manifestation (the self-communication in the case of the Son and Holy Spirit) of the divine Three in human history, whether together or separately, for the purposes of our salvation. By “immanent Trinity” we mean Father, Son, and Holy Spirit in their inner, eternal life, considered in itself. Starting with the economic Trinity, we can glimpse something of the immanent Trinity. Only by referring to the incarnation of the Son and the sending of the Holy Spirit can we say that the economic Trinity is the immanent Trinity and vice-versa. Outside these historic, salvific events, the immanent Trinity remains an apophatic mystery.
(i) The Trinity is revealed in the life of Jesus of Nazareth and the manifestations of the Holy Spirit as these were witnessed by the communities of disciples and recorded by them in the New Testament. The triadic expressions found in the Old Testament have Trinitarian meaning only on the basis of a Christian reading of them in the light of the New Testament.
(ii) As they appear in the New Testament, Father, Son, and Holy Spirit are always mutually related and reciprocally implied. The Father sends the Son into the world; the Son feels himself of one being with the Father; the Holy Spirit is also sent into the world by the Father, at the Son’s request. The Holy Spirit takes what is of the Son and enables us to know the Son; it teaches us to cry, “Abba, Father.”
(iii) The triadic formulas of the New Testament, especially that in Matthew 28:19, show a way of thinking that always associates the divine Three in the work of salvation. This and similar formulas helped in the later elaboration of Trinitarian doctrine.
4. The central problem of Trinitarian doctrine is this: how to express the fact that the divine Three are one God. Faith says: Father, Son, and Holy Spirit are really three and distinct; but they are always related; they are one God. How to equate trinity in unity and unity in trinity?
5. Three solutions put forward are unacceptable to Christian faith because they fail either to preserve trinity, or to maintain unity, or to keep the equality between the Three.
(i) Tritheism: affirms the existence of three gods, separate and distinct, each eternal and infinite. This interpretation preserves trinity: however, besides containing serious philosophical errors, it destroys unity.
(ii) Modalism: Father, Son, and Holy Spirit are three pseudonyms of the same, single God, or three modes of presentation (masks) of the same divine substance. God would be three only for us, not in God’s self. This interpretation (Sabellianism) preserves unity, but abandons trinity.
(iii) Subordinationism: Strictly speaking, there is only one God – the Father. The Son and Holy Spirit receive their divine substance from the Father in subordinate form, so that they are not consubstantial with the Father but rather creatures adopted (adoptionism) to share in his life. This interpretation (Arianism) denies the equality of the Three, since the Son and the Holy Spirit are not fully divine.
6. The orthodox Christian reply is expressed in basically philosophical terms drawn from the prevailing culture and says: God is one nature in three Persons, or, God is one substance in three hypostases. The concepts nature and substance (or essence) denote unity in the Trinity; the concept person and hypostasis safeguard trinity in unity.
7. There are three classic currents of thought that seek to deepen this expression of faith by elaborating a doctrine of the Trinity: Greek, Latin, and modern.
(i) Greek: This starts from the Father, seen as source and origin of all divinity. There are two ways out from the Father: the Son by begetting and the Spirit by proceeding. The Father communicates his whole substance to the Son and the Holy Spirit, so both are consubstantial with the Father and equally God. The Father also forms the Persons of the Son and the Holy Spirit in an eternal process. This current runs the risk of being understood as subordinationism.
(ii) Latin: This starts from the divine nature, which is equal in all three Persons. This divine nature is spiritual; this gives it an inner dynamic: absolute spirit is the Father, understanding is the Son, and will is the Holy Spirit. The Three appropriate the same nature in distinct modes: the Father without beginning, the Son begotten by the Father, and the Spirit breathed out by the Father and the Son. The three are in the same nature, consubstantial, and therefore one God. This current runs the risk of being interpreted as modalism.
(iii) Modern: This starts from the Trinity of Persons – Father, Son, and Holy Spirit. But the Three live in eternal perichoresis, being one in the others, through the others, with the others, and for the others. The unity of the Trinity means the union of the three Persons by virtue of their perichoresis and eternal communion. Since this union is eternal and infinite, we can speak of one God. This interpretation runs the risk of being seen as tritheism. We follow this current: fist, because it starts from the datum of faith – the existence of Father, Son, and Holy Spirit as distinct and in communion; and second, because it allows a better understanding of the universe and human society as a process of communication, communion and union through the interpenetration of creatures with one another (perichoresis). This interpretation strengthens the cause of the oppressed struggling to liberate themselves so that there can be greater sharing and communion.
8. Trinitarian language is highly figurative and approximative, the more so in that the mystery of the Trinity is the deepest and most absolute mystery of the Christian faith. Expressions such as “cause” referring to the Father, “begetting” referring to the Son, and “breathing-out” applied to the Holy Spirit, like “processions,” “mission,” “nature,” and “persons” are analogical or descriptive and do not claim to be causal explanations in the philosophical sense. The inner meaning of such expressions shows the diversity exists in the divine reality on one hand, and the communion on the other. We use terminology hallowed by tradition and also biblical terminology because they are less ambiguous and because they are used by some modern theologians. Some of those terms are: revelation, acceptance, communion.
9. The conceptual language of devout reason is not the only means of access to the mystery of the Trinity. The church has also developed the symbolic language of imagery. This emphasizes the significance the Trinity has for human existence, particularly in its longing for wholeness. This wholeness is the mystery of the Trinity. It is best expressed through symbols which spring from the depths of the individual and collective unconscious, or form humanity’s common religious stock. Symbolic language does not replace conceptual language, but is basic to the formation of religious attitudes.
10. Humanity, male and female, was created in the image and likeness of the triune God. Male and female find their ultimate raison d’être in the mystery of Trinitarian communion. Though the Trinity is transsexual, we can use male and female forms in speaking of the divine Persons. So we can say “maternal God-Father” and “paternal God-Mother.”
11. The Filioque question (the Holy Spirit breathed out by the Father and the Son, or through the Son) is bound up with the theological sensitivity of the Eastern church vis-à-vis the Western, as is a certain type of terminology adopted by one or the other (the Father as source or principle of all divinity – Eastern; or the Son as sourced source – Western). Another theological strand starting from the perichoresis of the divine Persons would have not only Filioque, but Spirituque and Patreque as well, since in the Trinity everything is triadic.
12. By virtue of perichoresis, everything in the Trinity is trinitarian – shared by each of the divine Persons. This does not preclude there being actions proper to each of the Persons, through which the property of each person is shown.
(i) The proper action of the Father is creation. In revealing himself to the Son in the Spirit, the Father projects all creatable beings as expressions of himself, of the Son and of the Holy Spirit. Once created, all beings express the mystery of the Father, have a filial nature (since they come from the Father), a brotherly and sisterly nature (since they are created in the Son) and a “spiritual” nature (meaning full of meaning, of dynamism, since they were created by the power of the Holy Spirit).
(ii) The action proper to the Son is the incarnation in Jesus of Nazareth, through which he divinizes all creation and redeems it from sin. Through the Son, maleness shares in divinity.
(iii) The action proper to the Holy Spirit is the “pneumatiation” through which created life is inserted into the mystery of the life of the Trinity, and redeemed form all threat of death. Through the Holy Spirit, femaleness is introduced into the divine mystery.
13. From the perichoresis-communion of the three divine Persons derive impulses to liberation: of each and every human person, of society, of the church, and of the poor, in the double – critical and constructive – sense. Human beings are called to rise above all mechanisms of egoism and live their vocation of communion. Society offends the Trinity by organizing itself on a basis of inequality and honors it the more it favors sharing and communion for all, thereby bringing about justice and equality for all. The church is more the sacrament of Trinitarian communion the more it reduced inequalities between Christians and between the various ministries in it, and the more it understands and practices unity as co-existence in diversity. The poor reject their impoverishment as sin against Trinitarian communion and see the inter-relatedness of the divine “Differents” as the model for a human society based on mutual collaboration – all on an equal footing – and based on individual differences; that society’s structures would be humane, open, just, and egalitarian.
14. The universe exists in order to manifest the abundance of divine communion. The final meaning of all that is created is to allow the divine Persons to communicate themselves. So in the eschatological fullness, the universe – in the mode proper to each creature, culminating in man and woman in the likeness of Jesus of Nazareth and Mary – will be inserted into the very communion of Father, Son, and Holy Spirit. Then the Trinity will be all in all.
The Holy Trinity is a sacramental mystery. As sacramental, it can be understood progressively, as the Trinity communicates itself and the understanding heart assimilates it. As mystery it will always remain the Unknown in all understanding, since the mystery is the Father himself, the Son himself, and the Spirit itself. And the mystery will last for all eternity.