"In the beginning was the Word, and the Word was with God, and the Word was God."
Jesus was the Word (which was God,) the Creator, the Life, and the Light among men. In Jesus no darkness can dwell.
Jesus came into our dark and sinful world. The world did not know Him. He came to His own people. They did not receive Him. But to all who did receive Him and who believed in His name, He gave eternal life and they became children of God; children who walk in the light of His Word.
Moses taught the 10 Commandments; God's perfect, Holy standard. The people broke them over and over. Because of their sin, they had to offer up to God sacrifice upon sacrifice, year after year. God was teaching the people that they could not save themselves; they needed a Savior.
Jesus became that. Because we are hopeless sinners, He offered grace upon grace. He kept every one of the 10 Commandments perfectly and then gave Himself up for our sakes by becoming the perfect, final sacrifice. He gave His life so we who believe in Him could have eternal life.