To the religious establishment of the day, Jesus uttered the shocking claim, "Before Abraham was born, I am." I imagine that was the first time those words had been uttered since the burning bush. Nothing could have been more offensive to the ears of a first-century Jew--little wonder that Jesus got nailed to a tree.
To his disciples, Jesus said that he was "the vine," and "the way, the truth and the life." And to the crowd, he announced "I am" the gate, the good shepherd, the bread of life, and the resurrection and the life. But prior to these proclamations, Jesus revealed to all: "I am the light of the world. Whoever follows me will never walk in darkness, but will have the light of life."
As an educated and trained physicist, I have always been profoundly impressed by the metaphor of light for Jesus. In my opinion, nothing in the material universe reveals as much about the nature of God.
At the surface level of understanding, light is a source of illumination that opens our senses to the visible world. At a deeper level, "light" opens our minds to rational argument, understanding and truth. Light is also a source of life. Biological life, as we know it, would not exist without the carbon food cycle dependent on photosynthesis. However, it wasn't until the advent of the 20th century that some of the hidden mysteries of light would be made known.
In 1905 Albert Einstein rattled the cages of the scientific academy with the theory of Special Relativity. While most people associate Einstein's theory with the relative nature of time, the foundation of relativity is the constancy of light: for all observers in all frames of reference, the speed of light will be measured as 186,000 miles per sec. As I have previously noted, this makes light an ideal measurement standard with several profound characteristics.
Because the speed of light will be measured the same by all observers, regardless of their speed, their measurement of time must vary. For the extreme case of an explorer blitzing through the cosmos at the speed of light, time will stop--he will not only become ageless, he will become omnipresent, for as he goes from point "A" to point "B", he will experience both locations, and every place in-between, as they were when he set out on his journey...even if his departure point and destination are separated by ten billion light-years!
A source of illumination, revelation, life. An ideal Measure; constant, ageless, omnipresent. Astonishing! Thousands of years before Einstein, the apostle John used a metaphor for Jesus that could only be fully appreciated at the advent of modern physics. Like I said, as a former physicist I'm in awe over the inspired testimony: "In him was life, and that life was the light of men."
(What do you think of the metaphor of light? Post your comments here.)