The image is dynamic. There is a sense of movement. It is difficult to tell if the circles are radiating from the figure or, in some sense, moving toward and into him. Perhaps it is possible for it to be both. The Sapphire figure seems to be coming toward us. The whole effect makes the picture pleasant to look at.
The Man in Sapphire Blue has an attraction that goes beyond the blueness. The figure has an aura of compassion. The eyes are large and somewhat sad. The hands are offered open in a sort of invitation as if for an embrace, beckoning us to enter with him into the mystery. Hildegarde, like other medieval people of deep prayer – both male and female – refers to the “embrace of God’s maternal love.” There is tenderness in that phrase that matches the face and posture of the figure.
The Man of Sapphire is Jesus. In this a vision of the Trinitarian mystery, Jesus Christ is the focus. The flame and light as the Father and Spirit, though they encircle and draw attention to Christ, are in the background. While Jesus Christ is the only begotten Son of the Father, he becomes the prism through which we know the Father. And while Jesus is full of the Spirit, that Spirit is most fully known to us as the Spirit of Jesus Christ.
In the vision, the Sapphire Christ hangs down from the background circle of light which represents the Father – the “font of divinity” according to the Eastern Orthodox tradition. It is as if Jesus, the Son, is in the womb of the Father. Proceeding from center of the background circle of the Father is another circle, orange like fire, which Hildegarde identifies as the Holy Spirit.
Deborah Vess suggests:
The circles are superimposed on a square, which has four corners, and is, therefore, reminiscent of the earth itself. Also, squares provide a feeling of stability. The union of the circle and square, a common motif in many cultures, represents that harmony of heaven and earth. As Christ is in the center, the suggestion here is that Christ unites heaven and earth -- he was fully divine, but also fully human. [This can be found here].
The vision reveals something of the mystery of God as Father, Son, and Holy Spirit as we have come to know God in the light of Jesus Christ. But what God is like beyond that remains a mystery.
More on the Trinity:
The Friendship Dance
The Threefold all-kindly