"Awake, thou that sleepest, and arise from the dead, and Christ shall give thee light." (Knox)
~Ephesians 5:14
Summer is in full swing, and the Sun is out for the longest time of the year, lighting our days (and early nights). The Sun is a special character in the storied, creative symbology of Christianity. From the earliest days of the Church, in the Divine Liturgy (called the Holy Mass in the Latin rites we are familiar with), and customarily in all prayer, every member of the congregation faced the same direction - to the East. This directionality of liturgy was a tradition adapted from the Jewish custom of worshipping facing the Temple in Jerusalem. It gained a clearer, more profound, and important significance in the new Christian paradigm: the "facing" was toward the rising Sun, a symbol of the Heavenly Jerusalem. In addition, the Resurrection of the Lord instilled a new supernatural symbolism to the natural import of the rising Sun: namely, that the True Sun, the Son of God, had risen from the dead and given new Life to the world, a singular extra-cosmic revolution of the Life-giving Christ that superseded the perennial cosmic revolution of the Sun's light-giving role. There is an identification of light and warmth with Life, Truth, and Love, and the significance of the rising is of course pretty pat. Throughout at least the first millennium of the Church, in both the East and West, all churches were built with the altar facing the East - recalling that the priest led the people facing the same direction - to the Sun in the Heavens.
With the development of the tabernacle in the Western (Roman) Church, in which God was actually reposed so that the church building became not only a place where He descended at every Consecration but also a continual dwelling of the Word Made Flesh, the significance of the directionality, where everyone was looking, evolved. They were no longer merely looking to the East - symbolically looking to God; they were looking to the Tabernacle - literally looking to God. By Divine Providence, we have in English the harmonious homophony of the "Sun" and the "Son", which allows for our ears the metaphor to reach to a whole other level. In our language, then, Christians in the Roman Church were no longer looking merely at the Sun in the Heavens, but at the Son of Heaven, in the Tabernacle, throughout the Mass. Sadly, this newfound significance of the Tabernacle also contributed to the loss of meaning of facing the Eastern Sun, so that some churches began to be built facing in other directions in later centuries. But the much more important significance of facing God in the Tabernacle remained - until 1970, when some Masses errantly began to be said facing the people, and Tabernacles in some churches were displaced.
It is significant that one saint during the Counter-Reformation (whose name, unfortunately, escapes me) compared the Mass to the Sun that rises on the world daily to shed its rays of grace. St. Pio of Pietrelcina also said that it would be easier for the world to exist without the Sun than without the Mass - he might have said, in English, "...than without the Son." Consider the shape of the liturgy these saints were speaking of, which remained unbroken for nearly two millennia: 1) Mass was by canon law required to be read or sung in the morning (because it was when the Lord rose from the dead). 2) The Latin Church had perfected its tradition of using an unleavened, circular, white host as the bread matter for the Sacrament (unlike the Eastern Church, which uses to this day leavened loaves). 3) At the Consecration, the custom arose of elevating the Sacred Host over the priest's head, he himself still facing the Tabernacle (this Elevation became enshrined perpetually in the Roman rite after Pope St. Pius V's official rubrics). What emerges from the shape of this holy liturgy is an extraordinary augmentation of the cosmic and solar symbolism, which permeated the sense of the faithful and popular piety: every day for centuries, a Western Christian attending Mass early in the morning would observe a white circle being lifted up high over the head of the priest, shining spotless life on the whole world, reuniting Heaven and Earth, redeeming Creation and transforming it into something new - in other words, he would see the Son rise.