Matthew 18:6

“But whoever shall cause one of these little ones who believe on me to stumble, it is profitable for him that a great millstone should be hanged about his neck, and that he should be sunk in the depth of the sea.”

No wonder then that it is seen as so dreadful to cause such a one ‘to stumble' or ‘be ensnared' (skandalizo - the skandalon was the trigger that set off a trap or snare). For to cause such a young believer to stumble and fall to the ground is, as it were, to make Jesus stumble and fall to the ground. And Jesus says here that such behaviour deserves capital punishment of the most severe kind. Drowning was a Roman method of execution. And here the success of the drowning is ensured by having a huge millstone, in this case large enough to require a donkey to drive it, tied around the neck, so as to ensure that once the person has been thrown from a boat into the sea (or from a precipice, Jesus is concerned with the end not the method), he sinks without trace. Death at sea was an abhorrent thought to a Jew for such a person had no grave (compare Revelation 20:13). And yet that form of death would be better for a man than the fate that is in store for someone who makes His little ones stumble, or go astray. The idea behind the word ‘to stumble' includes ‘to be entrapped'. Either way the little one has been led into sin by the words or example or failure to care of someone who should have known better.

The ludicrous picture of the huge millstone emphasises the seriousness of the offence, for no one would even consider using such a large weight for such an execution (the thickness of rope that would be required would be as thick as the neck). It must thus be seen as signifying ‘making doubly sure'. There is no escape from it.

But how are little ones caused to stumble? In context it is by those who are themselves not providing the right example. By not walking in humility and lowliness, by not revealing Jesus, by not shining as lights in the world (Matthew 5:14; Matthew 5:16), they are thus leading others astray. For how we behave speaks louder than what we say, and one good example is worth a thousand words. However we may no doubt also see behind this false teaching which leads people in the wrong way, for that is equally condemned in Scripture (2 Peter 2:1), unnecessary disparagement, acting towards young believers with a wrong attitude, lack of pastoral care and so on. Compare how Jesus described Peter as becoming a stumbling block to Jesus Himself (Matthew 16:23).