2 (It was that Mary which anointed the Lord with ointment, and wiped his feet with her hair, whose brother Lazarus was sick.)
3 Therefore his sisters sent unto him, saying, Lord, behold, he whom thou lovest is sick.
4 When Jesus heard that, he said, This sickness is not unto death, but for the glory of God, that the Son of God might be glorified thereby.
5 Now Jesus loved Martha, and her sister, and Lazarus.
6 When he had heard therefore that he was sick, he abode two days still in the same place where he was.
7 Then after that saith he to his disciples, Let us go into Judæa again.
8 His disciples say unto him, Master, the Jews of late sought to stone thee; and goest thou thither again?
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.
10 But if a man walk in the night, he stumbleth, because there is no light in him.
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.
12 Then said his disciples, Lord, if he sleep, he shall do well.
13 Howbeit Jesus spake of his death: but they thought that he had spoken of taking of rest in sleep.
14 Then said Jesus unto them plainly, Lazarus is dead.
15 And I am glad for your sakes that I was not there, to the intent ye may believe; nevertheless let us go unto him.
16 Then said Thomas, which is called Didymus, unto his fellowdisciples, Let us also go, that we may die with him. (John 11)
After asking for many years about verses 9-10, God revealed the meaning to me. This mystery is unlocked contextually. The context is that the Lord is beckoned to return to Bethany, which at this point has become hostile territory. His life is in such danger there that the apostles believe that if he returns he will be killed (verses 8 and 16). The Lord replies with verses 9-10.
The twelve hours of the day are the twelve apostles. They are always in the light, or the presence of the Lord, because they accompany him wherever he goes. Because they are always with him, they have him to protect them from danger. Lazarus, on the other hand, was not accompanying the Lord. These three "walked in the night" because they did not physically accompany Jesus, despite being his disciples. Why they did not accompany him I do not know, however it seems they had some purpose in staying where they were due to Jesus' visits to them.
How does this apply today? How many of us "walk in the day"? Yet all of us can. We choose to walk in the night because we choose to live a lifestyle that does not allow a habitation with God. A habitation with God is very different from the normal Christian life. The normal Christian's interaction with God is limited to a few occasional and brief encounters with his spirit. Even those who have seen Jesus once cannot say they really know him. To know God, you must acquire a habitation with him. What does this mean?
16 And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever;There are three degrees of relationship with God here. The first is to have the Holy Ghost dwell with you. The second is to have the Lord manifest himself to you. The third is to have the Lord abide with you. The second experience is a visitation. The third is a habitation.
17 Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.
21 He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him.
23 Jesus answered and said unto him, If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him. (John 14)
David had a habitation with God. He said "...I foresaw the Lord always before my face, for he is on my right hand, that I should not be moved:" (Acts 2:25) Imagine what it would be like to see the Lord always. To be able not only to speak with him (not just to him) and see him always. That is what is promised to all the faithful over and over again.