From this, we now see what our greatest joy should be and for what, above all, we ought to give thanks to God, namely, that He has enlightened us inwardly through His Word and Spirit and has brought us to a saving knowledge of Christ. The Lord Christ, as “Wisdom” (1 Cor. 1:24), understood best what an inexpressible blessing that was, which is why He rejoiced over it so earnestly and gave thanks to His heavenly Father for it so intensely. We do not understand or ponder it with such seriousness, which is why our spiritual joy and thanksgiving are also so much colder. But this is certain: The more the light of the saving knowledge of God increases, the more the spiritual joy and praise of God also grows within you. Indeed, if the natural light causes us to rejoice when it rises after the dark night, or when we are brought out of the dark dungeon to the very light of day, should not the heavenly, spiritual light of divine knowledge that the Lord God has kindled in our hearts, darkened by nature, cause us to rejoice much more, yes, immeasurably more? The natural light illumines us for a short time in this fleeting life and causes us to participate “with the saints in the light” (Col. 1:12).
As high as heaven is above the earth, so much more precious and noble should we also esteem the heavenly light of divine knowledge than the natural light. The one for whom that heavenly light has not yet appeared and arisen still sits in darkness and will be cast out into the outermost darkness, and the natural light of the sun or of his own understanding will not be able to prevent it; only the heavenly light will do. If we want to come to this light, then we must not place too much trust in the natural light of our understanding, which is deceptive and misleading. We must not consider ourselves wise, but we should recognize that the natural light is darkness before God, and the world’s wisdom is foolishness. Many people fool themselves in this regard; they think that the true, heavenly light of the saving knowledge of God has arisen in their heart, but it is only a slender ray of the natural light which does not go or lead beyond nature. O heavenly Light, shine on us and drive out the darkness from our hearts! O bright Morning Star, arise in our heart! Teach us, O divine Wisdom! We will gladly be infants and willingly yield to Your enlightening!
(Sermon for St Matthias-February 24, Postilla Volume 3 by Johann Gerhard, Repristination Press, page 51-52)