The ability to illustrate a spiritual event in the physical world is the central truth of icon painting. Here, that which belongs to the lower world -- the physical materials of wood and paint-- has been transformed and brought to new life by the higher, spiritual world of divine light and energy contacted through contemplative prayer. The colours play on our sensibilities like musical harmonies and enable us, through inner resonance, to open to a higher power. The icon's symmetry and balanced form corresponds to the meditative state of the mystic, where the exterior is passionless and without movement. This external stillness preconditions the inner state, and it is here that the higher life appears appears. At the centre of the painting is a strong, vertical axis around which flow the movements and energies expressed by colour and form.
Source: Richard Temple, Icons: Divine Beauty, Saqi Books 2004, p 87