This polyptych is mystical, not to say esoteric, in intention, and is imbued throughout with both spiritual and intellectual signification. When opened, it represents the communion of saints, which is "the new heaven and the new earth", in the words of the Revelation of St John. Thus the central panel of the lower tier portrays the saints symbolizing the eight Beatitudes gathered round the altar where the sacrifice of the Lamb is taking place, at the centre of the heavenly garden which has sprung from His blood.

To left and right, in the foreground, are two processions facing one another. One of these is made up of the Old Testament patriarchs and prophets, and the other of figures from the New Testament. Some of them are kneeling, barefoot. Behind them is assembled the hierarchy of the Church - popes, deacons and bishops, wearing sumptuous jewelry and clothes in the bright red of martyrdom. In the background are two further groups, facing each other as if they had just emerged from the surrounding shrubbery. These are, on one side, the Confessors of the Faith, tightly packed together and almost all dressed in blue; and on the other side, the Virgin Martyrs, holding out palm fronds and wearing in their hair crowns of flowers of a kind traditionally worn by young girls at certain holy ceremonies. In the middle of the panel, around the altar where the Lamb spills forth his blood, angels kneel, holding the emblems of His Passion. Grace is symbolized by a radiant dove hovering in the sky, and eternal life is represented by a fountain in the foreground. A paradisiacal landscape runs across all five lower panels, uniting them in a single composition. It is strewn with plants from different countries and flowers of different seasons. The central panel is vibrant with green, while those to the sides are more arid and rocky. The horizon sits high in the frame and is closed off by groves of trees, behind which clusters of fairy-tale buildings can be made out, representing the heavenly Jerusalem.