The moment one becomes a Christian their whole life begins to look differently to them. The new Christian sees him or herself in the light of God's Word. That light makes a tension in the life of the believer, a tension, which aides in sanctification. The Christian begins to see his or her sin in the light of the Word, which brings misery. The Christian also sees that he or she is an image bearer of God. The Psalmist said, "I am fearfully and wonderfully made."
This new light from Scripture, and applied by the Holy Ghost, causes a new new mind to see God's dealings in various disciplines and spheres of life. John Calvin said that when he was converted it was as if the Lord made his mind teachable. This is the truth for all those who truly love God. The mind becomes teachable and the mind begins to see things in the light of God's great standard.
There is an old Puritan way to discuss this light on the mind- a maid is cleaning the master's house because of a great gathering that he is having in the morning. She looks upon her work with joy, but in the morning she and the master are devastated. The home is a dusty mess! Why is the home so dusty? After night the sun rose and shone brightly into the estate. In the light of the sun, the maid was able to see the dust covering everything. This is how it is with humanity as well. Man thinks that he is pretty good, that he keeps his life in good order- but in the Light of The Son, man is revealed to be a filth covered sinner. In thy light shall we see light.
In thy light shall we see light.
Light is the glory of life. Life in the dark is misery, and rather death than life. The Lord alone can give natural, intellectual, and spiritual life; he alone can make life bright and lustrous. In spiritual things the knowledge of God sheds a light on all other subjects. We need no candle to see the sun, we see it by its own radiance, and then see everything else by the same lustre. We never see Jesus by the light of self, but self in the light of Jesus. No inward intelligence of ours leads us to receive the Spirit's light, but the rather, it often helps to quench the sacred beam; purely and only by his own illumination, the Holy Ghost lights up the dark recesses of our heart's ungodliness. Vain are they who look to learning and human wit, one ray from the throne of God is better than the noonday splendour of created wisdom. Lord, give me the sun, and let those who will delight in the wax candles of superstition and the phosphorescence of corrupt philosophy. Faith derives both light and life from God, and hence she neither dies nor darkens.
-Charles Spurgeon, 1885