Maggots, grubs, worms. When I imagine one or many of these nasty slimy buggers living inside my body — unseen, feeding off my flesh, slowly rotting me out — I feel deeply disgusted. If I knew I had a worm, I would do anything to remove the alien invader, and fast. But what if I couldn’t ever get it out? 
This is precisely the image Jesus uses to describe those who cause others to sin and fail to cut out what leads them to sin. He contrasts the kingdom of God with Gehenna, “where the worm does not die.” If we can stomach it for a moment, there is much wisdom in this nauseating metaphor. 
First, sin is always parasitic. It feeds on what is good like a worm in a host. It’s not symbiotic or additive, as virtue and love always are. Sin invades, devours, and damages the sinner. Second, sin is always social. No matter how hidden, it quietly eats away at others — usually the most poor and vulnerable, the “little ones,” as the Lord says. How healthy it is for us to acknowledge this! Our gossiping, greed, over-indulgence, lying, pride, laziness, lust for power and reputation, and so on … they do not add anything to life. They are worms eating away at others and ourselves. 
We cut out these filthy parasites through genuine repentance and bold action. Imagine the peace and relief that follows the removal of a sickening worm from your body. How much greater is the peace we enjoy when the spiritual worms are gone for good. We’d never wait to act against physical parasites. Neither should we with the worms of sin. — Father John Muir ©LPi