These false teachers are dried-up springs. They are a mist blown around by a storm. Gloomy darkness has been kept for them.
They arrogantly use nonsense to seduce people by appealing to their sexual desires, especially to sexual freedom. They seduce people who have just escaped from those who live in error.
They promise these people freedom, but they themselves are slaves to corruption. A person is a slave to whatever he gives in to.
People can know our Lord and Savior Jesus Christ and escape the world's filth. But if they get involved in this filth again and give in to it, they are worse off than they were before.
It would have been better for them never to have known the way of life that God approves of than to know it and turn their backs on the holy life God told them to live.
These proverbs have come true for them: "A dog goes back to its vomit," and "A sow that has been washed goes back to roll around in the mud."