The titles and labels applied to Jesus in the NT were generally drawn from the religious environment of the day. The name titles, “Logos” and “Son of Man” have been discussed here before and demonstrated to have been in use by Greek and Jewish writers as personifications of concepts pieced together from Greek philosophy and OT exegesis.
Elaine Pagels wrote an interesting article that reveals how G.John’s use of the name/title “light of the world” has a similar heritage. Hating tying as I do, Ill just summarize briefly the main points.
Anyone reading Genesis 1 notices the fact that light is created before the sun and moon and stars. Just what was intended by the author has been discussed before as well but it is important to know that there was much theorizing about Gen 1 in the centuries BC though the first centuries AD. Influential thinkers like Philo had drawn elaborate conclusions about the “light” in verse 3. The light had taken on it’s own life you might say. Here’s a passage from Philo book VII :
(31) And the invisible divine reason, perceptible only by intellect, he calls the image of God. And the image of this image is that light, perceptible only by the intellect, which is the image of the divine reason, which has explained its generation. And it is a star above the heavens, the source of those stars which are perceptible by the external senses, and if any one were to call it universal light he would not be very wrong; since it is from that the sun and the moon, and all the other planets and fixed stars derive their due light, in proportion as each has power given to it; that unmingled and pure light being obscured when it begins to change, according to the change from that which is perceptible only by the intellect, to that which is perceptible by the external senses; for none of those things which are perceptible to the external senses is pure.
Philo was not alone in personifying the “light” into a quasi being with connections with God. Rabbis of the first century and beyond entertained the idea that light here meant more than physical light, it rather was an emanation from God that was responsible for the rest of creation. The Kabala goes on to great lengths in this regard combining this personified Light with the Adam character. There was in fact an understanding that Adam was the light and was perfected in communion with God until this light was lost (through various theoretical means) leaving only a physical being. The Primordial light was variously identified with the Divine Image and Adam in a way that few of us today would have guessed by using only our Bibles.
Another current of thought also influenced this concept. A body of literature, drafted by Egyptian writers that distinctly show influece from Hellenized Judaism, called the Corpus Hermeticum expounded even clearer this personified Light as the Primeval man. Here is an example from Poimandres the Shepard of Man usually dated to the first century AD:
That Light, He said, am I, thy God, Mind, prior to Moist Nature which appeared from Darkness; the Light-Word (Logos) [that appeared] from Mind is Son of God.
What then? - say I.
Know that what sees in thee and hears is the Lord's Word (Logos); but Mind is Father-God. Not separate are they the one from other; just in their union [rather] is it Life consists.
Thanks be to Thee, I said.
So, understand the Light [He answered], and make friends with it.
Note that here the Light was called the Son of God. The idea of a personified light easily found a home in Christianity. It was certainly part of early Gnostic Christianity. A number of camps of Gnostics utilizd this personified ‘Light” and ‘Primal man’ imagery in association with the mystical Christ figure. Irenaeus derailed these ‘heretics’ at length and conveniently summarized their views in his works. His attacks were generally due to the polytheistic overtones of the resulting fusion of mythology and Jewish exegesis.
Here is a sample of these reviews:
1. Others, again, portentously declare that there exists, in the power of Bythus, a certain primary light, blessed, incorruptible, and infinite: this is the Father of all, and is styled the first man. They also maintain that his Ennoea, going forth from him, produced a son, and that this is the son of man-the second man. Below these, again, is the Holy Spirit, and under this superior spirit the elements were separated from each other, viz., water, darkness, the abyss, chaos, above which they declare the Spirit was borne, calling him the first woman. Afterwards, they maintain, the first man, with his son, delighting over the beauty of the Spirit-that is, of the woman-and shedding light upon her, begat by her an incorruptible light, the third male, whom they call Christ,-the son of the first and second man, and of the Holy Spirit, the first woman.
2. The father and son thus both had intercourse with the woman (whom they also call the mother of the living). When, however, 314 she could not bear nor receive into herself the greatness of the lights, they declare that she was filled to repletion, and became ebullient on the left side; and that thus their only son Christ, as belonging to the right side, and ever tending to what was higher, was immediately caught up with his mother to form an incorruptible Aeon. This constitutes the true and holy Church, which has become the appellation, the meeting together, and the union of the father of all, of the first man, of the son, of the second man, of Christ their son, and of the woman who has been mentioned.
The G. Thomas reveals a distinct influence in very early Christian times to interpret Genesis similarly yet without the colorful mythology and implied polytheism of the Egyptian writings, it is likely contemporary with our G.John. Here is a passage:
77 Jesus said, "I am the light that is over all things. I am all: from me all came forth, and to me all attained.
Split a piece of wood; I am there.
Lift up the stone, and you will find me there."
Note that Jesus calls himself the light that not only created all things but exist in all things.
It was in such a context that our G.John was spawned. The author certainly had theological differences with all the above examples, just as they had with each other, yet the religious environment and the contemporary influences both Jewish and otherwise shaped his conception of Christ as the Genesis ("in the beginning")"Light" . So now when we read about how ‘the light came into the world’ to reveal the true nature of the Father, we can better appreciate that he was not using the expression as a simple metaphor. No he was drawing from a very deep religious tradition and in his own way trying to reshape it. An effort now generally wasted on modern readers.