"In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by Him, and without Him was made nothing that was made. In Him was Life, and the Life was the Light of men, and the Light shines in darkness, and the darkness did not comprehend it." - John 1:1-9
The greatest of our mysteries is the mystery of the Blessed Trinity, of three Persons in one God, God the Father, God the Son, God the Holy Ghost. To use the words of the Athanasian Creed: "The Person of the Father is one, of the Son a second, of the Holy Ghost a third. But of the Father, and of the Son, and of the Holy Ghost the Divinity is one and the same, the glory is equal, the majesty is co-eternal. As is the Father, so is the Son, so, too, the Holy Ghost. Uncreated the Father, uncreated the Son, the Holy Ghost, too, uncreated. Unlimited the Father, unlimited the Son, unlimited the Holy Ghost. Eternal the Father, eternal the Son, eternal the Holy Ghost. . . . Omnipotent the Father, omnipotent the Son, omnipotent the Holy Ghost. . . . God the Father, God the Son, God the Holy Ghost. . . . The Father the Lord, the Son the Lord, the Holy Ghost the Lord. Yet not three Lords, but only one."
God the Father alone completely knows Himself. He so completely knows Himself that His very understanding of Himself is more than an image. When I know another I have in my mind an image of that other, a perfect reproduction of him so far as my mind can reproduce him, but still never more than an image, however alive with my life it may be. But in God the Father this image of Himself is perfect. He understands Himself so completely that the image of Himself is complete. And as the image in my mind lives by my life, so does the perfect image of Himself in His perfect and all-comprehending mind live by His perfect life - and is; is "the Father's understanding of Himself, begotten by that understanding, in the same identical nature as the Father"; is the Son of God, "born of the Father from all eternity."
"The Father beholds the Son, God of God, Light of Light, true God of true God, altogether like to and equal to Himself, and the possessor with Him of His whole Nature and Deity. The Son beholds the Father, the Supreme and Eternal Good, of Whom He is Himself begotten eternally without imperfection, from Whom He receives the Divine Nature and all that He has. Thus the Father loves the Son, and the Son loves the Father with infinite and eternal love. The love of the Father and of the Son is mutual and one, because each Person loves the other, one because the Nature of the two is not twofold, but one and the same. As the intelligence of the Father is infinitely fertile, and generates the Son, so the love by which the Father loves the Son, and by which the Son loves the Father, is infinitely fertile, and breathes the Holy Spirit. The Eternal Father and the Eternal Son communicate to the Holy Spirit, by this act of love. Their own whole Substance and Nature, and thus produce, in their Deity, another and distinct Divine Person, the same in Nature with themselves " (H. J. Coleridge).
- from The Prince of Peace: Meditations, by Archbishop Alban Goodier, SJ. It has the Nihil Obstat of F. Thome Bergh, O.S.B., Censor Deputatus, and the Imprimatur of Canon Edmund Surmont, Vicar General, Diocese of Westminster, England, 16 November 1915