Light
is,
God; Christ; the Gospel;
saving knowledge; the Body of Christ;
a born-again
Christian.
Also: Fire. Light.
Also:   Lustrous; bright; full of light;
luminous.  A candle, a portable
lamp or other illuminator.

Also: To kindle; set on fire.

(See more about 'Light'
in, Webster's 1828)

The light of the body is the eye:
if therefore thine eye be single,
thy whole body shall be full of light.
But if thine eye be evil,
thy whole body shall be full of darkness.
If therefore the light that is in thee be darkness,
how great is that darkness!

  Matthew 6:   
22-23 
  
God is light ((I John 1:5)
Christ is the true light (John 1:9)
The Gospel is light (II Cor 4:4)
Saving knowledge is light (Isaiah 8)
Prosperity and happiness are light (Isaiah 58:8)
The understanding or judgment is light (Matthew 6:22)
The gifts and graces of Christians are light (Matthew 5:15)
A true Christian, a person enlightened is light
(Ephesians 5:8)

(See Webster's 1828
American Dictionary
of the English Language
for more on 'light'.)    

Ye are the light of the world. 
A city that is set on an hill cannot be hid. 
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.  Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.

Matthew 5:
14-16
For ye were sometimes darkness,
but now are ye light in the Lord:
walk as children of light:
(For the fruit of the Spirit is in all goodness
and righteousness and truth;)
Proving what is acceptable unto the Lord.
And have no fellowship with
the unfruitful works of darkness,
but rather reprove them.

Ephesians 5:8-11
This then is the message which we have heard of Him,
and declare unto you,
that God is light, and in Him is no darkness at all. 
If we say that we have fellowship with Him
and walk in darkness, we lie, and do not the truth: 
but if we walk in the light as He is in the light,
we have fellowship one with another, and
the blood of Jesus Christ His Son cleanseth us from all sin
If we say that we have no sin,
we deceive ourselves, and the truth is not in us. 
If we confess our sins,
He is faithful and just to forgive us our sins,
and to cleanse us from all   
unrighteousness.   

I John 1:5-9      
That was the true Light,
which lighteth every man that cometh into the world. 
He was in the world, and the world was made by Him,
and the world knew Him not.  
He came unto His own, and His own received Him not. 
But as many as received Him,
to them gave He power to become the sons of God,
even to them that believe on His name:
which were born, not of blood,
nor of the will of the flesh,
nor of the will of man,
but of God.

John 1:9-13