Proverbs 20:27

The spirit of man [is] the candle of the Lord
The rational soul of man is a light set up in him; this is what is commonly called the light of nature; it was a bright and burning light at first, but through sin is become a very feeble one; by which men have only a glimmering view of divine things, of God and his worship, and of what he would have done, or not done; by this light men do but grope after him, if happily they may find him and know his will; it is but like a candle light at best, in comparison of divine revelation, or the Gospel of the grace of God, which has shone out like the sun in its meridian glory; and especially in comparison of the sun of righteousness, Christ Jesus, and the light of the divine Spirit; yet this is a light set up by the Lord, a candle of his; it comes from the Father of lights, he is the author and maintainer of it; it is a spirit and understanding which is by the inspiration of the Almighty; see ( Genesis 2:7 ) ( Job 32:8 ) ( Zechariah 12:1 ) ; searching all the inward parts of the belly;
or heart; the thoughts, intents, and purposes of it; which are the things of a man that only the spirit of man knows; by this candle, or light, he can look into his own heart, the inmost recesses of it, and reflect upon his thoughts and schemes, and judge in some measure whether right or wrong; there is a conscience in man, which, unless seared, passes sentence on what is in man, or done by him, and either excuses or accuses; see ( 1 Corinthians 2:10 1 Corinthians 2:11 ) ( Romans 2:14 Romans 2:15 ) .