In Chapter 21 of the book of Revelation, St John describes his vision of the heavenly Jerusalem. This new Jerusalem which St John saw descending out of heaven is, in fact, the human being, the new, regenerated human being; the foundations of precious stones on which the city rests are the virtues, and its gates are pearls.

Why pearls? Because pearls are symbols of purity, and all the ‘gates’ of the human body – the eyes, ears, mouth, etc. – are gates that must be guarded and kept absolutely pure, so as to ensure uninterrupted communication with heaven.
Those who work according to the precepts of the Gospels and the new methods of our teaching transform their old Adam into the Christ. That is what the new Jerusalem is.

We have to work as masons to build the temple, but this temple is not built of stone and mortar; it is built of the subtlest materials of love, gentleness, humility, generosity and kindness. At all the most solemn and sacred moments of a person’s existence, when they experience a powerful impetus or emotion of a spiritual nature, they emanate pure elements and particles, and it is these elements and particles that constitute the building materials they use in the construction of their inner temple.

Omraam Mikhael Aivanhov – ‘The Fruits of the Tree of Life’, Vol. 32
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Building the inner sanctuary, Chap. 25