All the disciples understood that when the Lord said, "Let us go into Judea," He was not speaking of the small, comparatively quiet and safe village of Bethany. He meant that He was going again into that hostile land where His murder was being prepared.
On the one hand, the Lord calms their fear. On the other, He points to the sense of duty, humanly speaking, which stands above everything. Yet at the same time He also reveals to the disciples the higher divine mysteries.
"I must work the works of Him who sent Me while it is day. The night is coming, when no one can work. As long as I am in the world, I am the light of the world" (Jn 9:4-5).
The Lord is "the light of the world" (Jn 8:12). The same thought is repeated in verses 9 and 10 of the present chapter.
The Lord had to remain on earth only for a definite time. Within this brief epoch, or "line of time," appointed by divine Providence, the great events had to be accomplished which brought about the salvation of the human race.
In pointing to this brief time, the Lord also shows that humanity's future blessedness lies in this work, done while the light shines.
Only this time of the Lord's dwelling on earth poured upon all humanity's future life that bright light of righteousness, love, and faith which shines for us amid the night of this world.
It is very important to note the Lord's expression concerning the one who stumbles: "the light is not in him" (ἐν αὐτῷ).
The Lord did not say that he stumbles because there is no light in the world. "The light shines in the darkness, and the darkness did not comprehend it" (Jn 1:5).
Rather, he stumbles because there is no light in the soul of the unbeliever.
Unbelievers have walked, and still walk, in the night of their soul. They stumbled, and still stumble, over that stone of stumbling and offense for them.
Yet that very stone became the foundation of the Church of God on earth. See Mt 21:42-44; 1 Pet 2:7; Rom 9, and in the Old Testament compare Ps 117:22 and Is 28:16.
Therefore, in speaking of day and night, the Lord means, on one side, eternal day and eternal light. On the other, He means the darkness of unbelief.
The brief sojourn of God in human form upon the earth is likened to a day. This day is eternal for believers. Those who walk by the light of this day do not stumble.
But in order to kindle this day forever, the Lord, during the comparatively brief time of His life, was creating a new life for man.
This He calls working. Man's walking in the day He calls abiding in the light of the day, so that he may not stumble.
But man's walking outside faith and outside the ways of God the Lord calls darkness and stumbling.
The most terrible moment of this darkness was the temporary permission, granted by the Lord, for the "power of the prince of darkness, the prince of this world" (Lk 22:53; Jn 14:30).
At that time the light of the world was not extinguished. It was only temporarily hidden from the people by the power of darkness, so that it might shine forth in the solemn, glorious, unflickering light of Christ's joyful Resurrection.