"I am the one who gives light to the world." This means Jesus brings God's true message to the world and rescues people from the darkness of their sin. (See: [[rc://en/ta/man/translate/figs-metaphor]])
"Everyone who follows me." This is a figurative way of saying "Everyone who does what I teach" or "Everyone who obeys me." (See: [[rc://en/ta/man/translate/figs-metaphor]])
"Walking in darkness" is a figurative way of talking about living sinfully. AT: "will not live as if he were in darkness" (See: [[rc://en/ta/man/translate/figs-metaphor]])