Hildegard’s first theological text, the Scivias, includes this wonderful vision of the trinity:
"Then I saw a bright light, and in this light the figure of a man the color of a sapphire, which was all blazing with a gentle glowing fire. And that bright light bathed the whole of the glowing fire, and the glowing fire bathed the bright light; and the bright light and the glowing fire poured over the whole human figure, so that the three were one light in one power of potential."
And again I heard the living Light, saying to me: ….
"Therefore you see a bright light, which without any flaw of illusion, deficiency, or deception designates the Father; and in this light the figure of a man the color of a sapphire, which without any flaw of obstinacy, envy, or iniquity designates the Son, Who was begotten of the Father in Divinity before time began, and then within time was incarnate in the world in Humanity; which is all blazing with a gentle glowing fire, which fire without any flaw of aridity, mortality, or darkness designates the Holy spirit, by Whom the Only-Begotten of God was conceived in the flesh and born of the Virgin within time and poured the true light into the world. And that bright light bathes the the whole of the glowing fire, and the glowing fire bathes the bright light; and the bright light and the glowing fire pour over the whole human figure, so that the three are one light in one power of potential."