The Holy Apostle and Evangelist John the Theologian, whom we commemorate today, proclaims: "God is light, and in Him is no darkness at all. If we say that we have fellowship with Him and walk in darkness, we lie, and do not tell the truth." And indeed, the whole goal of the Christian life is to purify our hearts and minds, that we might be enlightened--by the grace of God--with the light of Truth. We are called, therefore, to strive to overcome the sinful passions, that our spiritual eyes might be opened, that having been illumined by the grace of God, we might be delivered from the tyranny of the Prince of Darkness.
According to the first Book of Moses, "In the beginning God created the heavens and the earth.... And darkness was upon the face of the deep.... And God said, Let there be light: and there was light. It is plain to see, therefore, that Light is the first and foundational principle of God's creative work. Take note, however, that this Light is revealed before the creation of the sun and moon. It is not, therefore, the material light we perceive with the physical eyes of our bodies. (Nor can it be, as some assert, the uncreated Light of God, but rather a created light that emanates from God and permeates the entire created order).
If we reference any concordance of the Scriptures, we will discover that the theme of light versus darkness runs like a golden thread throughout the divine Scriptures--both Old and New. The works and the powers of darkness, and the very Prince of Darkness himself--the Devil--are set in contrast and opposed to the Light of divine revelation granted unto the sons and daughters of light in the waters of Baptism. For it is only by receiving into ourselves the Light of Truth that we may hope to be delivered from the darkness of ignorance. "Ye shall know the Truth, and the Truth shall make you free."
The eyes of the man born blind were opened when he did as Christ commanded and washed them in the pool of Siloam, but it was by means of the immaterial Light of God that he recognized Christ as the promised Messiah and the fulfillment of the long-awaited hopes of Israel. The Pharisees, on the other hand, saw clearly the light of the material world, but their spiritual eyes were utterly darkened by the passions of pride and vainglory.
Truly "the light of Christ illumines all," as the priest proclaims in the Presanctified Liturgy. But just as a man born blind cannot conceive of what darkness is, since he has no concept of light and therefore has no means of comprehending the contrast, nor can those who have willingly separated themselves from the love of God in Christ Jesus begin to comprehend the nature of that darkness into which they have unwittingly descended. For how can we "see" darkness if we have no concept of the light? It is only through God's gift of sincere and genuine repentance that we may be granted, by the grace of God, the illumination of our spiritual eyes and the salvation of our souls in God's eternal Kingdom.