Jesus here refers to the eyes of the mind—the understanding. How often, when a difficult matter has been explained, we say, "Oh, yes; I see it all now!" and yet the eyes behold no new object. We mean that we now understand what puzzled us so much before.
Thus, in these two verses we are told about minds that are darkened, and also about understandings that are enlightened with the light of life.
"If the light that is in thee be darkness, how great is that darkness!" If the windows are bricked up, no ray of light can force an entrance, even at noonday, into the darkened rooms; or, if the casements are thickly curtained, or closely shuttered, how dark the house must be! So sin of some kind—pride, prejudice, or superstition—darkens the sinner's understanding, shuts out the light of heavenly truth, and lulls him to sleep in the arms of the wicked one—the sleep of death.
People often tell us that we can do something to enlighten our own understanding. We can unfasten the shutters, or draw back the curtains, and let in the light. Alas! unless the grace of God has reached us in its almighty power, we do not want the light. Our deeds are evil, and the light that makes them manifest is hateful (see John iii. 18, 19). The thief, the murderer, the coiner of bad money, and all who are knowingly guilty of wrong-doing, love darkness, secresy, and concealment "rather than light"; and this is our "condemnation," as fallen creatures—we love the darkness, and we shun God's holy light. "Having the understanding darkened, being alienated [or estranged] from the life of God through the ignorance that is in them, because of the hardness of their heart" (Eph. iv. 18). Such was our state by nature. What are our feelings now?
Saul of Tarsus, as a Pharisee, was learned, intelligent, and moral; but how dark, how blind, he was in those days! Jesus, God's beloved Son, was the Object of his hatred. The altogether Lovely One had no beauty at all for him, and the children of God he viewed as enemies whom he felt bound to conquer and destroy. How great his darkness was—the darkness of prejudice and pride!
Chiniquy, the Romish priest, of whom some of us have heard so much, was blinded by superstition for many a year, and even the light of the Bible, as he read and studied it, could not remove that darkness till God Himself said, "Let there be light," and made the night of superstitious error flee away.
Then minds are blinded as was Balaam's of old, and the Pharisees, to whom Christ said, "If ye were blind"—that is, if they had not heard His words, and seen His works (see John xv. 22, 24)—"ye had not had sin"—you would have been comparatively free from blame—"but now ye say, We see; therefore your sin remaineth."
They hated the light they had, and closed their eyes against it. As the proverb says, "None are so blind as those who will not see."
But "God, who commanded light to shine out of darkness [at the world's creation], hath shined in our hearts," wrote the Apostle Paul (2 Cor. iv. 6), "to give the light of the knowledge of the glory of God in the face of Jesus Christ."
The once blinded Pharisee could see now, and how different were all his feelings! His own righteousness was cast away. Jesus was precious to his heart, and Christians were his "own company," his beloved friends.