Sorry to say this:
Tritunggal memang adalah Misteri.
http://www.newadvent.org/cathen/15047a.htm
The trinity as a mystery
The Vatican Council has explained the meaning to be attributed to the term mystery in theology. It lays down that a mystery is a truth which we are not merely incapable of discovering apart from Divine Revelation, but which, even when revealed, remains "hidden by the veil of faith and enveloped, so to speak, by a kind of darkness" (Constitution, "De fide. cath.", iv). In other words, our understanding of it remains only partial, even after we have accepted it as part of the Divine message.
The Vatican Council further defined that the Christian Faith contains mysteries strictly so called (can. 4). All theologians admit that the doctrine of the Trinity is of the number of these. Indeed, of all revealed truths this is the most impenetrable to reason. Hence, to declare this to be no mystery would be a virtual denial of the canon in question. Moreover, our Lord's words, Matthew 11:27, "No one knoweth the Son, but the Father," seem to declare expressly that the plurality of Persons in the Godhead is a truth entirely beyond the scope of any created intellect. The Fathers supply many passages in which the incomprehensibility of the Divine Nature is affirmed. St. Jerome says, in a well-known phrase: "The true profession of the mystery of the Trinity is to own that we do not comprehend it" (De mysterio Trinitatus recta confessio est ignoratio scientiae — "Proem ad 1. xviii in Isai."). The controversy with the Eunomians, who declared that the Divine Essence was fully expressed in the absolutely simple notion of "the Innascible" (agennetos), and that this was fully comprehensible by the human mind, led many of the Greek Fathers to insist on the incomprehensibility of the Divine Nature, more especially in regard to the internal processions. St. Basil, Against Eunomius I.14; St. Cyril of Jerusalem, Catechetical Lectures VI; St. John Damascene, Of the Orthodox Faith I.2, etc.).
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Salam,
The formation of the Trinitarian dogma
249 From the beginning, the revealed truth of the Holy Trinity has been at the very root of the Church's living faith, principally by means of Baptism. It finds its expression in the rule of baptismal faith, formulated in the preaching, catechesis and prayer of the Church. Such formulations are already found in the apostolic writings, such as this salutation taken up in the Eucharistic liturgy: "The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all."
"IN THE NAME OF THE FATHER AND OF THE SON AND OF THE HOLY SPIRIT"
232 Christians are baptized "in the name of the Father and of the Son and of the Holy Spirit" Before receiving the sacrament, they respond to a three-part question when asked to confess the Father, the Son and the Spirit: "I do." "The faith of all Christians rests on the Trinity."
The dogma of the Holy Trinity
253 The Trinity is One. We do not confess three Gods, but one God in three persons, the "consubstantial Trinity". The divine persons do not share the one divinity among themselves but each of them is God whole and entire: "The Father is that which the Son is, the Son that which the Father is, the Father and the Son that which the Holy Spirit is, i.e. by nature one God." In the words of the Fourth Lateran Council (1215), "Each of the persons is that supreme reality, viz., the divine substance, essence or nature."
http://www.vatican.va2:14 But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know [them], because they are spiritually discerned.
5:4 For whatever is born of God overcomes the world. And this is the victory that has overcome the worldour faith.
5:5 Who is he who overcomes the world, but he who believes that Jesus is the Son of God?
5:6 This is He who came by water and blood, Jesus Christ; not only by water, but by water and blood. And it is the Spirit who bears witness, because the Spirit is truth.
5:7 For there are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one.
Bagi dunia memang misteri, namun tidak bagi iman kita, yang telah mengalahkan dunia
Mari kita rayakan misteri iman kita, yang telah mengalahkan dunia! Amin.