Isaiah 10: 17 calls Him ôr yiśrā'ēl - the Light of Israel. But Jesus took that even further in the New Testament, calling Himself phos o cosmos - the Light of the whole world. (See John 8: 12 and John 9: 5) The apostle John begins his gospel by telling us that Jesus was the true Light (John 1: 9), the One who shines in the darkness and brings the light of life to all mankind.
And it's not just a temporary light; there are verses in Isaiah and in Revelation that say He is the Everlasting Light, the One who is with us for all eternity. See, for example, Isaiah 60: 19 - 20.
What really makes a difference, though, is that He is not just a general light for mankind, for Israel or for the church. He is also ever present as source of light and direction for individual believers. David proclaims in Psalm 27: 1 - The Lord is my Light and my Saviour/Salvation.
What are the implications of knowing God as my Light? It means I never need to walk in darkness; I don't need to be afraid of the unknown or of enemy ambush, because the Lord will be there at the right time to shine His light and to guide me.
Of course, one of the common ways He guides us is through His written Word, the Bible. The writer of another psalm says that God's Word is also a light for us, in the here and now as well as in making decisions about the future. "Your Word is a lamp (nîr) for my feet and a light (ôr) for my path." (Psalm 119: 105)
But Jesus also gave us a solemn warning. In telling us that He's the Light of the world, He promised that those who follow Him will never walk in darkness (John 8: 12), but He also warned that some people choose the darkness over the light because their actions are evil and they want to keep them hidden. (John 3: 19)
So the choice is clear. The Light is there and He's available to us, but we have to make a personal choice to follow Him and walk in the light.
