Take heed therefore that the light which is in you be not darkness.
Proverbs 16:25 There is a way that seemeth right unto a man, but the end thereof are the ways of death.
Proverbs 26:12 Seest thou a man wise in his own conceit? there is more hope of a fool than of him.
Isaiah 5:20,21 Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter! …
that the light within you
The "light" symbolizes spiritual truth, understanding, and the presence of God within a person. In biblical terms, light often represents purity, holiness, and divine revelation (John 1:4-5, Psalm 119:105). Jesus Himself is described as the "light of the world" (John 8:12), and believers are called to reflect His light. This phrase emphasizes the importance of internalizing God's truth and allowing it to illuminate one's life.
is not darkness.
Darkness represents sin, ignorance, and separation from God. In the cultural and historical context of the Bible, darkness is often associated with evil and moral corruption (Ephesians 5:8, 1 John 1:5-6). The warning here is against self-deception and the danger of allowing sin to obscure the truth. It calls for self-examination to ensure that one's understanding and actions align with God's will, avoiding the pitfalls of hypocrisy and false righteousness.
• Jesus has just said, “Your eye is the lamp of your body” (Luke 11:34), so His first command is a sober call to vigilance.
• Scripture repeatedly urges alertness:
– Mark 4:24 “Consider carefully what you hear.”
– Hebrews 2:1 “We must pay more careful attention, therefore, to what we have heard, so that we do not drift away.”
– Proverbs 4:23 “Guard your heart with all diligence, for from it flow springs of life.”
• The warning assumes personal responsibility. No one else can watch over your spiritual focus for you (Galatians 6:4–5).
• The adverb links Christ’s warning to the choice we make after hearing truth. It is the “therefore” that flows from revelation.
• Ephesians 5:15 captures the same flow: “Therefore be careful how you walk, not as unwise but as wise.”
• Jesus is saying, “Since spiritual perception matters so much, act on this right now.” Procrastination lets the enemy sow weeds among wheat (Matthew 13:25).
• “Light” pictures the life of Christ shining from the inside out (John 1:4; 2 Corinthians 4:6).
• When we receive Him, we become “children of light” (Ephesians 5:8) and His Word becomes “a lamp to my feet and a light to my path” (Psalm 119:105).
• The phrase assumes an interior reality—true faith transforms the core, not merely externals (Romans 12:2).
• Darkness here is spiritual blindness or self-deception—calling evil good, and good evil (Isaiah 5:20).
• Jesus repeats this thought in Matthew 6:23: “If your eyes are bad, your whole body will be full of darkness.”
• Practical safeguards against inner darkness:
– Examine yourself regularly in the light of Scripture (2 Corinthians 13:5; James 1:22–25).
– Walk in confessed, open fellowship with God and others (1 John 1:6–7).
– Keep short accounts with sin; hidden sin always dims perception (Psalm 32:3–5).
Luke 11:35 urges constant, personal vigilance so that the divine light we have received remains pure and unobstructed. By guarding our hearts, acting promptly on truth, nurturing Christ’s light within, and rejecting any compromise with darkness, we live as shining witnesses in a dark world and enjoy the full, unhindered fellowship that our Lord intends.
(35) Take heed therefore that the light . . .--Better, See to it whether the light that is in thee be darkness. This takes the place in St. Luke's report of St. Matthew's (Luke 6:23) "If the light that is in thee be darkness, how great is that darkness!" The warning is one which calls men to self-scrutiny. They need to examine their primary beliefs, their very intuitions of right and wrong, lest all they do should be vitiated at its very source. The call to do this implies that they must have a Light by which to judge their light, a Standard by which to test their standard, and that Light and Standard are found in the teaching of the Light that lighteth every man, in the recorded words and acts of the Son of Man.