This was cross-posted on my LJ, and will probably wind up on my Vox account's blog, as well. (I use the same name on Vox as I do LJ and here.)
Traditionally, on today's Feast of the Holy Trinity, the Athanasian Creed is read. This isn't just a creed; it's a thorough catechesis on the Mystery of the Holy Trinity. The text follows.
Whoever wishes to be saved, needs above all to hold the Catholic faith; unless each one preserves this whole and inviolate, he will without a doubt perish in eternity.
But the Catholic faith is this, that we venerate one God in the Trinity, and the Trinity in oneness; neither confounding the persons, nor dividing the substance; for there is one person of the Father, another of the Son, and another of the Holy Spirit; but the divine nature of the Father and of the Son and of the Holy Spirit is one, their glory is equal, their majesty is coeternal.
Of such a nature as the Father is, so is the Son, so also is the Holy Spirit; the Father is uncreated, the Son is uncreated, and the Holy Spirit is uncreated; the Father is infinite, the Son is infinite, and the Holy Spirit is infinite; the Father is eternal, the Son is eternal, and the Holy Spirit is eternal; and nevertheless there are not three eternals but one eternal; just as there are not three uncreated beings, nor three infinite beings, but one uncreated, and one infinite; similarly the Father is almighty, the Son is almighty, and the Holy Spirit is almighty; and yet there are not three almightys but one almighty; thus the Father is God, the Son is God, and the Holy Spirit is God; and nevertheless there are not three gods, but there is one God; so the Father is Lord, the Son is Lord, and the Holy Spirit is Lord; and yet there are not three lords, but there is one Lord; because just as we are compelled by Christian truth to confess singly each one person as God, and also Lord, so we are forbidden by the Catholic religion to say there are three gods or three Lords.
The Father was not made, nor created, nor begotten by anyone. The Son is from the Father alone, not made nor created, but begotten. The Holy Spirit is from the Father and the Son, not made, nor created, nor begotten, but proceeding.
There is, therefore, one Father, not three Fathers; one Son, not three Sons; one Holy Spirit, not three Holy Spirits; and in this Trinity there is nothing first or later, nothing greater or less, but all three Persons are coeternal and coequal with one another, so that in every respect, as has already been said above, both unity in Trinity, and Trinity in unity must be venerated. Therefore, let him who wishes to be saved, think thus concerning the Trinity.
But it is necessary for eternal salvation that he faithfully believes also the incarnation of our Lord Jesus Christ.
Accordingly, it is the right faith, that we believe and confess, that our Lord Jesus Christ, the Son of God is God and man. He is God begotten of the substance of the Father before time, and He is man born of the substance of His mother in time: perfect God, perfect man, consisting of a rational soul and a human body, equal to the Father according to His Godhead, less than the Father according to humanity.
Although he is God and man, yet He is not two, but He is one Christ; one however, not by the conversion of the Divinity into a human body, but by the assumption of humanity in the Godhead; one absolutely not by confusion of substance, but by unity of person. For just as the rational soul and body are one man, so God and man are one Christ.
He suffered for our salvation, descended into hell, on the third day arose again from the dead, ascended into heaven, sits at the right hand of God the Father Almighty; thence He shall come to judge the living and the dead; at His coming all men have to arise again with their bodies and will render an account of their own deeds: and those who have done good, will go into life everlasting, but those who have done evil, into eternal fire.
This is the Catholic faith; unless every one believes this faithfully and firmly, he cannot be saved. Amen.
The comments to the original post, linked above, contain some good links to the original Latin and an older English translation. I like this one, though, (it's also in my missal, but this post saved me having to type it out =-P ) because it's extremely straightforward, plain, easy to understand.
I close the post with the paragraph on this from my missal (the Daily Roman Missal put out by the Midwest Theological Union, with the Imprimatur of the head of my Archdiocese, Cardinal George):
Taking its name from St. Athanasius (+373), even though it is no longer attributed to him, this prayer enumerates the essential doctrines of Christianity, especially the mysteries of the Holy Trinity. St Teresa of Avila [a Carmelite nun and a great mystic of the Church, probably best known for her reform of her order and her writing The Interior Castle,] recounts a meditation on this creed as follows: "Once, when I was reciting the Quicumque vult, I was shown so clearly how it was possible for there to be One God alone and Three Persons, that it caused me both amazement and much comfort. It was of the greatest help in teaching me to know more of the greatness of God and of his marvels." (Life of St. Theresa of Jesus, 39.36)
I apologize for any typos I made in that that spell-check didn't catch; this still isn't bad for me typing without looking at either the keyboard or the screen! XD
