Answer
The Gospel of John records a remarkable event, as Jesus heals a man who had been born blind. In John’s retelling, one of the statements Jesus makes is that “we must work the works of Him who sent Me as long as it is day; night is coming when no one can work” (John 9:4).
In the context Jesus and His disciples were traveling, and as they passed by a particular location, Jesus saw a man who was blind from birth (John 9:1). Jesus’ disciples asked Him what was the cause of the man’s blindness—whether he had sinned before birth or whether his parents had (John 9:2). They perceived that the man’s blindness had to have been caused by sin, so they inquired as to whose sin resulted in his being born blind. Jesus responded by explaining that the blindness wasn’t a result of the sin of either, but the blindness was so that the works of God might be displayed (John 9:3). As Jesus offers that vital explanation, He adds that “we must work the works of Him who sent Me as long as it is day; night is coming when no one can work” (John 9:4). In this context it becomes apparent why we are told to work while it is day, as Jesus explains that, while He is in the world, He is the Light of the world (John 9:5).
The man in John 9 had lived in darkness all his life, being blind, but then Jesus came, bringing sight and light to this man’s life. In that same way, the world was in darkness to that point, but Jesus had come, and “in Him was life and that life was the light of men” (John 1:4). John adds that Jesus “was the true Light, which, coming into the world, enlightens every man” (John 1:9, NASB95). It seems that Jesus, by bringing sight to this individual, was illustrating how He provides light to all humanity. At the same time, He tells His listeners that we are to work while it is day (John 9:4).
Jesus is not prescribing just any kind of work; rather, He says, “We must work the works of Him who sent Me as long as it is day; night is coming when no one can work” (John 9:4). He is challenging His listeners that they should be doing the work of His Father as long as it is day—as long as Jesus is there, it is day—the Light of the world is there. He adds that there is a time coming when the work can’t be done because it will be night. It seems that Jesus is referring to the time coming when He would no longer be on earth, and then He would not be (personally) bringing the light to all—He was making the most of the opportunity He had to do the works that demonstrated who He was and who His Father was. In this case that meant miraculously healing this man who was born blind. The man’s blindness had been entirely for that moment, so that God’s glory could be displayed. At that moment Jesus was able to show His power over nature and to demonstrate that He is the Light who enlightens every person. So Jesus Himself was “working while it was day.”
The disciples were also learning that they needed to make the most of the opportunity—that they had the Light of the world with them. They needed to pay attention to Him, to learn from Him, so they could know Him and faithfully represent Him later. While we can’t “work while it is day” in the same way because Jesus is not personally here on earth (He is at the right hand of the Father awaiting His return one day), we still have been enlightened by Him—He is the Way, the Truth, and the Life (John 14:6). Like the disciples, we should look to Him, and like the disciples were encouraged to do—and like Jesus did—we should also make the most of the opportunity. Each opportunity is provided by God for His glory, so we need to consider how we can work while it is still day.