Passage
Jesus answered, Are there not twelve hours in the day? If any man walk in the day, he stumbleth not, because he seeth the light of this world.
John 11:9 (KJV)
Nearby Context
John 11:7 Then after that saith he to his disciples, Let us go into Judaea again.
John 11:8 His disciples say unto him, Master, the Jews of late sought to stone thee; and goest thou thither again?
John 11:9 Jesus answered, Are there not twelve hours in the day? If any man walk in the day, he stumbleth not, because he seeth the light of this world.
John 11:10 But if a man walk in the night, he stumbleth, because there is no light in him.
John 11:11 These things said he: and after that he saith unto them, Our friend Lazarus sleepeth; but I go, that I may awake him out of sleep.
Study Lenses
The verse centers on "world", "light", "jesus", "answered", "twelve", "hours", "walk", and "stumbleth". It is saying that the verse draws attention to "world" and "light", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 8's "His disciples say unto him Master the..." into verse 10's "But if a man walk in the...", so "world" and "light" belong inside that flow. In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "world" and "light" with trust shaped by these words, not by a vague optimism outside the passage.