What does Paul say believers are doing when they say nasty things about each other?
Paul says believers who say nasty things about one another are biting and devouring each other, effectively bearing false witness and forcing fellow believers to defend their character. He warns that this behavior will consume them, meaning they will be eaten up by those they treat as adversaries.
Les teaches that Galatians 5:15 is an admonition following the statement that all the Law is fulfilled in one word: “Love your neighbor as yourself.” He explains that biting and devouring one another primarily involves bearing false witness, since a person’s character can be destroyed in five minutes. Using the political system as an illustration, Les notes that a derogatory comment or innuendo can immediately put someone on the defense, and the public may treat that person as guilty until proven innocent. Paul tells believers this is the same thing they are doing to each other. Every time they say something nasty about a fellow believer, they are by implication putting that person in a place of defending their character. Paul warns them to be careful because it will eat them alive. If they bite and devour one another, they should take heed that they be not consumed—literally eaten up by those to whom they are being an adversary.
But if ye bite and devour one another, take heed that ye be not consumed one of another.