John 8:12

Then spake Jesus again unto them - Allowing the story about the woman taken in adultery to be authentic, and to stand here in its proper place, we may consider that our Lord, having begun to teach the people in the temple, was interrupted by the introduction of this woman by the scribes and Pharisees; and now, having dismissed them and the woman also, he resumes his discourse.

I am the light of the world - The fountain whence an intellectual light and spiritual understanding proceed: without me all is darkness, misery, and death. The Divine Being was, by the rabbins denominated, The light of the world. So in Bamidbar Rabba: "The Israelites said to God, O Lord of the universe, thou commandest us to light lamps to thee, yet thou art The Light of The World: and with thee the light dwelleth." Our Lord, therefore, assumes here a well known character of the Supreme Being; and with this we find the Jews were greatly offended.

Shall not walk in darkness - He shall be saved from ignorance, infidelity, and sin. If he follow me, become my disciple, and believe on my name, he shall have my Spirit to bear witness with his, that he is a child of God. He shall have the light of life - such a light as brings and supports life. The sun, the fountain of light, is also the fountain of life: by his vivifying influences, all things live - neither animal nor vegetative life could exist, were it not for his influence. Jesus, the Sun of righteousness, Malachi 4:2 , is the fountain of all spiritual and eternal Life. His light brings life with it, and they who walk in his light live in his life. This sentiment is beautifully expressed and illustrated in the following inimitable verse (all monosyllables except one word) of that second Spenser, Phineas Fletcher. Speaking of the conversion of a soul to God, he says: -

"New Light new Love, new Love new Life hath bred;

A Life that lives by Love, and loves by Light:

A Love to him, to whom all Loves are wed;

A Light, to whom the sun is darkest night:

Eye's Light, heart's Love, soul's only Life he is:

Life, soul, love, heart, Light, eye, and all are his:

He eye, Light, heart, Love, soul; He all my joy and bliss."

Purple Island, Can. I. v. 7.