This icon, written by Andrei Rublev in the xxx century, is considered to be the most theologically perfect icon ever made. It is the highest achievement of Russian art–and a masterpiece by any standards. It is based on the Old Testament story of Abraham unwittingly entertaining angels with perfect hospitality. Christians believe that this event is the first revelation of God in Three Divine Persons.
Rublev’s Trinity most fully expresses the dogma of the Trinity in artwork.
The three angels are used in the icon as a symbol of the Holy Trinity. Indeed, in iconography it is heresy to depict God the Father, whose face no one has ever seen. This symbolic rendition of the Trinity, as told in the Bible, is the only permissible way to show the figure of God the Father.
The figure on the left represents God the Father. Both of the others bow their heads towards Him. The One in the center represents Jesus Christ, the one on the right is the Holy Spirit. They are all in relationship with each other, looking at each other, each inclining their heads in attentiveness and love, sitting together around a small table as if at an intimate meal. Compositionally, the figures form a circle, a shape that is without beginning or end, complete in itself without any one part coming before the other. The three persons all look basically alike–because they are One.
Note also that the figure of Christ is blessing a cup/chalice at this heavenly banquet, and also, that within the “negative space” of the trio, His entire figure is enclosed in a chalicelike shape formed by the Father and Holy Spirit. Jesus wears the gold “band of authority” over His shoulder, representing His authority to reveal the Father to all of us.
There is a little rectangle in the table near the bottom center: it represents the entrance to heaven, to the heavenly banquet, for all of us. It is through the Eucharistic meal, and the cup of suffering and love, that we enter the kingdom of God. Imagine peeking through that entranceway, into the color, light, and glory of what is depicted in the icon!