There are two key words/concepts I take from the above verse – “light” and “follow”.
In researching this passage, I came across several interpretations of what light Jesus was referring too in this passage: (1) referring to the rising sun – what the sun was to the earth, he became to mankind, (2) referring to the golden lamps in the temple courts – he was the true light, able to enlighten the minds of men, or (3) referring to the pillar of cloud and fire which gave light and guided the Isrealites through the wilderness – he was the true guide to heaven through the wilderness of this world.
While I prefer the first interpretation, I think all three work well, and all illustrate the greatness of the light.
But the key to the passage, I think, is the “follow”. In this context, I do not think following means only copying and imitating, but rather, I think it means trusting and putting your faith in another – in this case, Jesus.
Therefore, it is not enough to merely gaze upon and admire the “light”. We must “follow” the light in order to seek true salvation. And if we follow the light in this manner, then we should use that light to illuminate an increasingly dark world. As followers of the light, the light of salvation is available to us, and is also available to others through us. Let us shine!