Jesus Christ is the light OF the world
¶ Then spake Jesus again unto them, saying, I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life.
As long as I am in the world, I am the light of the world.
I am come a light into the world, that whosoever believeth on me should not abide in darkness.
Being IN the world, a true child of God desires to be a light IN the world and not be part of its darkness
That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world;
Our calling as believers…
8 For ye were sometimes darkness, but now are ye light in the Lord: walk as children of light:
9 (For the fruit of the Spirit is in all goodness and righteousness and truth;)
10 Proving what is acceptable unto the Lord.
11 And have no fellowship with the unfruitful works of darkness, but rather reprove them.
12 For it is a shame even to speak of those things which are done of them in secret.
13 But all things that are reproved are made manifest by the light: for whatsoever doth make manifest is light.
14 Wherefore he saith, Awake thou that sleepest, and arise from the dead, and Christ shall give thee light.
…to take the light of Christ to the world and glorify our Father in Heaven.
14 Ye are the light of the world. A city that is set on an hill cannot be hid.
15 Neither do men light a candle, and put it under a bushel, but on a candlestick; and it giveth light unto all that are in the house.
16 Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.
My understanding – This light is not our own nor of any man, it is from God by His Son Jesus Christ, glorify God as His light shines on men.