"Who is among you that feareth the LORD, that obeyeth the voice of his servant, that walketh in darkness, and hath no light? let him trust in the name of the LORD, and stay upon his God. Behold, all ye that kindle a fire, that compass yourselves about with sparks: walk in the light of your fire, and in the sparks that ye have kindled. This shall ye have of mine hand; ye shall lie down in sorrow."
Verse ten may be applied three different ways. Firstly, it may be applied to Jesus Himself Who walked the dark road of separation as He became sin for mankind. On the cross he cried, "My God, my God, why hast thou forsaken me? why art thou so far from helping me, and from the words of my roaring (Psalm 22:1)?" For a brief time, the Father separated Himself from the Son Who willing became sin for man. Such were dark times; yet, even there, the Lord Jesus Christ trusted in the eternal promises of Jehovah as is evidenced by the latter part of Psalm 22. "My praise shall be of thee in the great congregation: I will pay my vows before them that fear him (Psalm 22:25)." The Savior trusted that God would not leave His soul in hell neither suffer His Holy One to see corruption (Psalm 16:10).
Secondly, this passage may be applied to any individual who wishes to follow Jehovah God in simple faith. Isaiah asks, "Who is willing to fear God only?" "Who is willing to obey the call to repentant faith as preached by every true prophet of God?" Outside of the Messiah's righteousness, everyone walks in darkness. Light and wisdom begin with the fear of the Lord (Psalm 111:10), and one demonstrates the validity of his or her godly fear by fleeing to the authority of God's sacrificial Lamb. The passage clearly gives a gospel call to each and every individual - encouraging him or her to "Trust in the LORD with all thine heart; and lean not unto thine own understanding (Proverbs 3:5)."
Thirdly, this verse may be applied to the believer who seeks comfort in the darkness of tribulation. Isaiah walked in dark days, and to one degree or another, every believer experiences the darkness and rejection of Satan's world. To such a person, God calls out and encourages trust in His ability to overcome. He encourages simple faith as he works practical sanctification in the lives of His people.
The last verse is a word of rebuke to the one who rejects the light of God and chooses the light of his own understanding. To reject God's light is to reject His Son and His authority. It is to choose the way of death, because apart from a relationship with the Light of this world (John 9:5) there is no hope. The Lord uses the familiar picture of a common fire. For a period of time, the fire of man's understanding may burn. For a time, it may exude some form of light; but eventually, it will go out - leaving its victim to stumble and be injured. The word behind sorrow pictures a place of pain and terror. Man's wisdom ends in darkness when the temporary light of its fading embers gives way.