This passage gives insight into the very nature of the gospel encounter. We see the genuine offer of the gospel, and the need and urgency to accept it, which the listeners can do; or they can reject it with full knowledge and remain in their sin.
“So Jesus said to them, For a little while longer the Light is among you. Walk while you have the Light, so that darkness will not overtake you; he who walks in the darkness does not know where he goes. While you have the Light, believe in the Light, so that you may become sons of Light. These things Jesus spoke, and He went away and hid Himself from them” (John 12:35-36).
These two verses give a clear picture of what is happening during the gospel encounter. The news of Lazarus being raised from the dead had created quite a crowd of both Jews and Greeks (12:9, 17-22). Vs. 34 reveals that Christ’s claims were met by more questions, but the time to answer such questions had passed; it was time to share the gospel.
First note the presence of the Light
The presence of the Light is seen in the phrase, the Light is among you (vs. 35a) and you have the Light (vs. 36a). Jesus is the Light of the world (John 8:12), and now they are in the immediate presence of the Light who enlightens every man (John 1:9). God not only enlightens through His presence, but every time the truth is shared in the power of the gospel (Rom 1:16).
Second, notice the requirement in the Light
Two statements identify what the hearers and all must do when enlightened. They need to Walk in the Light (vs. 35) and believe in the Light (vs. 36). Even though they were enlightened by the presence of the Light of Christ and His truth (John 1:9), that was not enough. They had to act, and the word believe is the same call to everyone who hears the gospel. This is the essence of all encounters with truth; one must believe in the Light who is Christ. That is the call of the gospel.
This highlights the fact that being in the presence of the light of truth enables one to understand and receive salvation, but it does not secure salvation. Paul, recounting why he was sent to the Gentiles said it was “to open their eyes so that they may turn from darkness to light and from the dominion of Satan to God” (Acts 26:18).
As seen here, the unsaved are not summoned by the gospel after they have been delivered from darkness, but rather while they are engulfed in the darkness of this world and their sinful hearts. The light shines, the gospel summons, by which God calls the sinner unto Himself. If someone is saved, it can be said that he was truly called “out of darkness into His marvelous light” (1 Pet 2:9). This is the sufficient call of the gospel; it summons the lost to respond by faith, and it gives every indication that they can and should respond even while yet in their sin.
Third, both words “walk” and “believe” are plural imperatives commands
Importantly, all of the pronouns you are plural in vs. 35-36. Therefore, Christ is commanding every person within the range of His voice to act, decide, obey, and believe. As seen here, the enlightenment of the gospel is offered unconditionally, but reception of the benefit of the gospel is indeed conditional. They must walk and believe while they have the Light.
This is vital to understanding the dynamic of the gospel encounter. God enlightens, enables, commands, and summons (draws), and everyone who hears is commanded to believe, which they can and should do; at least that is what the passage indicates apart from any theological importation. The dividing line is not between the elect and non-elect, a general external call and a particular internal call, but rather it is between hearing only and hearing followed by believing.
Fourth, note the urgency of His message
One can see the urgency of Christ’s plea in the words For a little while longer, while you have the Light (vs. 35), and again while you have the light (vs. 36). This pathos of Christ and the urgency seen here comports well with a temporary opportunity to believe and be saved, but it does not meaningfully do so within the doctrine of unconditional election. If unconditional election is true, there can be an urgency for believers to share the gospel in obedience to the command of Christ; however, there can be no actual urgency for the hearer to believe. To wit, the urgency to believe the message of salvation while you can before it is too late and you cannot believe does not exist in Calvinism; to suggest that such exists is misleading at best.
But the Scripture presents this as a very urgent and moving moment. Being illumined by the gospel affords the command and choice to walk in the Light, but that time is limited and only God knows the length of opportunity. In this pericope that time came very quickly “He went away and hid Himself from them” (vs. 36). The unpardonable sin is a haunting warning that opportunity is only For a little while longer (Matt 12:30-32; 21:33-46), not to mention the unknown time of death.
Fifth, the Light overcomes darkness
This includes both their fallen nature and environment. This is evident in that Christ is calling upon each person to believe and walk in the Light, and this while they are still in the bowels of the blackness of the soul, darkness of the world, and gloom of judgment.
Jesus said, “I have come as Light into the world, so that everyone who believes in Me will not remain in darkness” (John 12:46, italics added). “In Him was life, and the life was the Light of men. The Light shines in the darkness, and the darkness did not overpower it” (John 1:4-5). In man’s sinfulness, apart from the grace of God, he can only wander aimlessly in the brume of his own sin (35b). Man on his own will never emerge from the darkness into the light because in darkness he does not know where he goes. On his own, he will walk the broad road of unlimited paths of salvation, all of which lead to utter darkness and damnation.
The only hope for a person so encapsulated in the midnight of blackness, is when the light of the gospel shines into his hell-bound black heart, empowering and illumining the way out. Jesus spoke to the lost and said, “I am the Light of the world; he who follows Me will not walk in the darkness, but will have the Light of life” (John 8:12). Even though those to whom He speaks are in the cauldron of spiritual darkness, He promises that the one who will choose to follow Him will not remain in darkness. Taken at face value, the promise appears to be real and accessible to everyone who hears Him speak those words, both then and now. If someone, anyone, will simply believe that promise, Christ will deliver him from the settled dusk of judgment to the dawning light of the Son. This passage clearly indicates that those who hear these words can and should follow Him.
This call to believe, follow, walk, and obey does not come after regeneration, but rather it comes while a person is in the black hole of hell’s darkness, on the precipice of eternal damnation. It is there that God’s delivering light, which is empowered by God’s love, enables one to walk out of the darkest darkness into the light. It seems that this call to believe and walk in the light is what it gives every indication of being. That is a genuine obeyable command, an accessible offer to believe; if it is not, then it is nothing more than a cruel promise of a phantom opportunity.
While in darkness, the light of the gospel penetrates into the otherwise impenetrable darkness of sin and death, and one is thereby grace-enabled to see the way out. At that encounter, the one so enlightened can understand enough to walk out from the darkness by believing the gospel (John 3:20-21). This grace granted understanding does not mean that the person hearing the gospel and thereby given divine understanding understands all or even a lot. This is seen here in that all of their questions are not answered (vs. 34). Full understanding is neither possible nor necessary for one to experience salvation. The enlightenment is sufficient to convict one of sin, righteousness, and judgment (John 16:8-11), grant understanding of God’s offer in the gospel, and enable a person to exercise faith unto salvation.
Calvinism makes Jesus appear to offer a real chance for all who hear to repent, but actually if Calvinism is true, it is Jesus, as second member of the Trinity, who developed the exclusive plan of salvation that inviolably precludes everyone but the unconditionally elect. To say, as some Calvinists do, that Jesus gave a “good faith offer” because He, as the man Jesus, did not know everything and therefore He did not know they were not elect, is to miss the point.
For Jesus said, “The things I speak, I speak just as the Father has told Me” (John 12:49-50). No amount of relying upon a “good faith offer” can exonerate the Father from leading Christ to say such things if they were not true. Neither can one assuage the difficulty by saying that this group was either composed of all elect or non-elect since some did not believe (vs. 37) and some did (vs. 42). The truth is that Jesus spoke that way because the Father’s plan included every provision necessary to give everyone who hears the gospel the grace-enabled choice to flee the wrath to come and be eternally saved.
Sixth, the two reasons why one should believe and walk in the Light
We have seen the urgency of the gospel encounter, while you have the Light and now we graphically see the indeterminacy and the conditional nature of the gospel encounter in two purpose clauses, which are indicated by the word hina, translated so that. We see the indeterminacy negatively, so that darkness will not overtake you (vs. 35). Then we see it positively, so that you may become sons of Light (vs. 36).
Read without importation of prior theological commitments, these two clauses seem to rule out predetermined conclusions. They, as all who hear the gospel, are commanded to believe, walk in the light, so that they may become sons of Light believers, so that the darkness penetrated by the presence of the Light does not once again envelop them when the truth is gone. Even though they are children of wrath (Eph 2:3), imprisoned in spiritual darkness, at the moment of the gospel encounter, the cell door is opened and the way out is illumined; this so that they may become sons of Light, thereby avoiding being overtaken by total darkness again, which would leave them to wander aimlessly.
Critical to see is that, before enlightenment, as sinners they wandered aimlessly in the bowels of spiritual darkness. But in the gospel encounter, enlightenment, Christ commands them to believe so that the darkness will not overtake them. Indicating, at this moment of enlightenment, although still in darkness of sin, they are grace-enabled to believe and avoid being once-again overtaken by darkness of sin and judgment, and they can actually become children of Light.
What could be clearer than the truth that in the gospel encounter, God is so working to penetrate the darkness with the glorious Light of the gospel, where man is both commanded to believe and freed to do so? As mentioned, all verbs translated you (vs. 35-36) are in the plural form, which signifies that all are addressed and likewise commanded. All can become children of light and avoid being overcome with darkness. This is because in the gospel encounter, darkness looms portentously, but not controllingly; like a mountain lion awaiting the right moment to seize its prey, darkness rushes in when the light of the gospel is withdrawn.
Overtake is the word katalambánō, which is an intensified form of lambano. As used here, the meaning is overtake or to gain control of. It bespeaks of an ominous imminent cloud of uncertainty, death, and irreversible judgment which shadows every breath of every person. When it descends, the time for decision is vanquished because alone man is no match for the prince of darkness, the dark night of a fallen world, or the humanly impenetrable blackness of the human heart. Sometimes this word is translated “comprehend” as the NASV does in John 1:5, but in this passage the meaning is clearly to overtake, and is so translated. However, both meanings are true. Neither pure darkness, nor one in pure darkness, can comprehend nor overpower the Light.
It is true that the ruler of this world (John 12:31) leads world forces, rulers, and powers of this darkness (Eph 6:12). Satan does blind mankind to the gospel (2 Cor 4:4), seek to keep man under his power (Eph 6:12), and therefore enslaved to darkness (Eph 2:1-3). He does so with unbreachable effectiveness against man on his own. But as is vividly portrayed here, in the dynamic of the gospel encounter, the darkness of sin and Satan is completely subjugated to the power of the gospel of Jesus Christ.
Essential to understanding the dynamic of the gospel encounter is that it is obviously transpiring in the absence of a predetermined unalterable permanent work of grace for some and not for others. This warning is as meaningless as the offer of deliverance if unconditional election is true, Calvinistic creative claims to the contrary notwithstanding.
As seen here, the word of truth is never to merely inform, but always demands a response of either acceptance or rejection. The invitation is essential to the proclamation of truth because its omission beclouds the essence of the gospel. Because some abuse invitations, whether in personal witnessing or preaching, this should not lead to our disavowal of such any more than abuses of Christian love should cause us to abandon love. The invitation (call to follow Christ John 8:12) is essential to the gospel.
In the crucible of conflict for the soul of man, the Light of Christ penetrates into the darkest corridor of Satan’s power and man’s sin, and frees man provisionally so that he may truly experience God’s salvific love eternally. Yes, a sovereign God is capable of such, and a loving God is doing such!
This gospel encounter ends as most do. Some chose to believe and thereby became sons of Light (vs. 37), while others chose to remain in their unbelief and were accordingly overcome by the darkness once again (vs. 42). This is the nature of the gospel encounter.
 “Pertaining to a relatively brief extent of time a little while, for a little while, a short time, brief, briefly.” Johannes P. Louw and Eugene Albert Nida, Greek-English Lexicon of the New Testament: Based on Semantic Domains (New York: United Bible Societies, 1996), 642.
 katalambano: to gain control over to overcome, to gain control of. Johannes P. Louw and Eugene Albert Nida, Greek-English Lexicon of the New Testament: Based on Semantic Domains (New York: United Bible Societies, 1996), 473. Figuratively of darkness or evil, to come suddenly upon someone (John 12:35; 1 Thess. 5:4; Sept.: Gen. 19:19; 31:23; 1 Kgs. 18:44). Spiros Zodhiates, The Complete Word Study Dictionary: New Testament (Chattanooga, TN: AMG Publishers, 2000).
 Sometimes this word is translated “comprehend” as the NASV does in John 1:5, the NAS, KJV, and NKJV translates katalambano as “comprehend,” and the ESV and NIV translate it “overcome it.” It is translated by all of these as “realize” or “perceive” in Acts 10:34, and rightly so. This highlights the fact that in some contexts the word clearly means “overtake” and some “understand,” whereas some contexts leave room for translating it either “overtake” or “understand” (John 1:5).