Verses 1-5 introduce us to the “Word” while vv. 6-8 explain who John is. He came to bear witness about the light. The light is described in vv. 9-13. Verses 14-18 resume the “Word” theme in which we learn that the Word is none other than Jesus Christ (v. 17). Ryle says, “The five verses now before us contain a statement of matchless sublimity concerning the divine nature of our Lord Jesus Christ.”
All Bible students immediately recognize how John’s prologue resembles the opening words of Genesis. Verses 1-3 speak of the Word’s eternity (In the beginning was the Word…He was in the beginning with God), deity (and the Word was God), community (and the Word was with God), and creativity (All things were made through him, and without him was not any thing made that was made). The biography of the creator God who exists before He created in Gen. 1:1 emerges in greater detail in John’s prologue. God the Father eternally dwelt with the Eternal Logos, His Son. He was actively involved in creation.
In him was life only makes sense if all things were made through him. He who was in the beginning and was with God and is Himself God has life in Himself (cf. 5:26). The phrase and the life was the light of men may mean that the Word gives both natural (v. 9) and spiritual illumination (v. 18). But in John, the overwhelming emphasis is the saving light of Christ. Since life and light are probably co-extensive and since this life is not given to everyone, the light of men probably refers to the special saving light that men receive.
Verse 5 anticipates the light/darkness theme. The light shines in the darkness, and the darkness has not overcome it suggests that the light cannot be blocked and that the light of redemption will prevail. The antithesis between darkness and light is made clear. Later, we will find that men love darkness.
JWs say, “the Word was a god.” Though the definite article is not present, the context assumes it. In English, we might say, “He went to the house, garage, and backyard before he got back into his car.” Here, definite articles could be used or left out; the context assumes the garage is related to the house (“the garage” and not some random garage), etc.
There was a man sent from God, whose name was John indicates that John was divinely sent. John did not decide on his own but God Himself sent Him. John’s role was to bear witness and not be the light: He came as a witness, to bear witness about the light, that all might believe through him. He was not the light, but came to bear witness about the light. There should be no misunderstanding between the light and the one bearing witness to the light. The point of the witness bearing is that all might believe through him. We should all bear witness so that all might believe in Christ; the goal is not “church growth,” to validate our evangelistic zeal, to prove our skills, etc. We must yearn for men to believe in our Lord!
Ryle’s words are worth quoting because ministers of the gospel cannot presume for themselves some superior role or place.
Christian ministers are not priests, nor mediators between God and man. They are not agents into whose hands men may commit their souls, and carry on their religion by deputy. They are witnesses. They are intended to bear testimony to God’s truth, and specially to the great truth that Christ is the only Savior and light of the world. This was Peter’s ministry on the day of Pentecost. “With many other words did he testify.” (Acts 2:40.) This was the whole tenor of Paul’s ministry. “He testified both to the Jews and Greeks repentance towards God, and faith towards our Lord Jesus Christ.” (Acts 20:21.) Unless a Christian minister bears a full testimony to Christ, he is not faithful to his office. (J. C. Ryle)
The Word and the Light are one, Jesus Christ. We read that the true light, which gives light to everyone, was coming into the world. The true light to everyone is John’s way of speaking about saving knowledge. Carson says,
What is at stake, rather, is the objective revelation, the ‘light’, that comes into the world with the incarnation of the Word, the invasion of the ‘true light’. It shines on every man, and divides the race: those who hate the light respond as the world does (1:10): they flee lest their deeds should be exposed by this light (3:19-21). But some receive this revelation (1:12-13), and thereby testify that their deeds have been done through God (3:21).
The coming is the incarnation and His ministry. He was not universally accepted. He was in the world, and the world was made through him, yet the world did not know him. He came to his own, and his own people did not receive him. The light/darkness antithesis already introduced becomes more specific. The Word came to the very world that was made through him. Yet, it did not receive Him. We read that his own people did not receive him which probably means the Jewish people. The phrase He came to his own also suggests He came to His own property (which He made).
Verses 12-13 however modify vv. 10-11. In general, the world rejected Him and yet, some did receive him, that is, those who believed in his name. These who believed, he gave the right to become children of God. Though they believed and became children of God, we find that such an act was not a human decision who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.
The eternal Word became flesh which boldly declares His incarnation. “Flesh draws attention to the entry of the Word into the full flow of human affairs. The divine Word had become the human Jesus.” (IVP Commentary) The phrase and dwelt among us alludes to the fact that the Word pitched his tabernacle among us (pitch a tent, tabernacle, etc. from the verb dwelt). John indicates that since the Word dwelt among men, he can say and we have seen his glory, glory as of the only Son from the Father, full of grace and truth. As the tabernacle housed the glory of God so the Word dwelling among men enabled John and the people to see the Word’s glory which was, full of grace and truth (an allusion to Ex. 34:5-7, love [covenant love] and faithfulness [or truth]).
Verse 15 reiterates the point made in vv. 6-8. John bore witness about him, and cried out, “This was he of whom I said, ‘He who comes after me ranks before me, because he was before me.’” John came to do this and in this verse, he does it and declares the preeminence of Jesus the Word.
The Word who is full of grace and truth graciously gives of Himself: For from his fullness we have all received, grace upon grace. John does not only bear witness to the light but declares that he has received from the light grace upon grace. Carson believes it should be translated as “grace instead of grace.” This grace replaces the previous grace. So the sentence For the law was given through Moses; grace and truth came through Jesus Christ does not mean no grace was present but only that in comparison, grace and truth in all its fullness came through Christ. Carson states it this way,
But the law that was given through Moses, and the grace and truth that came through Jesus Christ (v. 17), alike sprang from the fulness of the Word (v. 16), whether in his pre-existent oneness with the Father, or in his status as the Word-made-flesh. It is from that ‘fulness’ that we have received ‘One grace replacing another’. It is in this sense that v. 16 is an explanation of v. 14 (it begins with hoti, ‘for’ or ‘because’): we have seen his glory, John writes, because from the fulness of his grace and truth we have received grace that replaces the earlier grace—the grace of the incarnation, of the Word-made-flesh, of the glory of the Son ‘tabernacling’ with us, now replacing the grace of the antecedent but essentially promissory revelation. The ‘we’ who have received this new grace may have begun with John and the earliest eyewitnesses (cf. 1:14), but it now includes all who share the same faith (cf. 20:29).
Finally, we read that No one has ever seen God; the only God, who is at the Father’s side, he has made him known. This Word made flesh made God the Father known (made him known). The word for known is exegesis, Jesus is the exegesis of God or narrates God. He alone can do that because No one has ever seen God but the Word was always at the Father’s side.
The culmination of this prologue in v 18 is intended to remind the reader of v 1. There was no other possibility of our knowing God except through Jesus Christ, the Word. The statement no–one has ever seen God is a reflection from the OT. Even Moses was not allowed to see him. In this, therefore, the revelation of Jesus is infinitely superior since he is the one who has made God known.
 Carson says, “It speaks not of the Word serving as (potential) light for every man, but of giving light to every man.”
 “Believers receive the power to become children of God in the sense of God’s covenant people. John is not talking of natural descent (13). There is here an allusion to the new birth, which recurs more explicitly in ch. 3. Since spiritual birth is different from physical birth, John excludes sexual means (human decision, a husband’s will).” (IVP Bible Commentary)
 IVP Commentary