For everyone who does evil hates the light, and doesn't come to the light, lest his works would be exposed.
First, The deadly and destructive nature of sin, which is implied here. The guilt of sin is like the pain of the biting of a fiery serpent; the power of corruption is like the venom diffused thereby. The devil is the old serpent, subtle at first (Genesis 3:1), but ever since fiery, and his temptations fiery darts, his assaults terrifying, his victories destroying. Ask awakened consciences, ask damned sinners, and they will tell you, how charming soever the allurements of sin are, at the last it bites like a serpent, Proverbs 23:30-32. God's wrath against us for sin is as those fiery serpents which God sent among the people, to punish them for their murmurings. The curses of the law are as fiery serpents, so are all the tokens of divine wrath.