What does Matthew 18:9 mean?

Jesus has pronounced "woe," God's judgment, on those who place temptation in the path of His "little ones," believers in Jesus. He has said temptation is a necessary part of life, but He is now telling believers to go to great lengths to keep themselves from giving in to temptations to sin (1 Corinthians 10:13).

Does Jesus really want His followers to cut off hands or feet or to tear out their eyes in order to avoid sinning? No. He is using the communication technique of hyperbole to communicate to His disciples the degree of seriousness with which they should deal with sin. Jesus did not want any of them to have a casual attitude to the deadly consequences of sin.

Was Jesus really warning that any believer who sins—ever—will go into the "hell of fire"? Again, we would say no. If He had meant these two things to be taken literally, first-century Christians would have been maimed and blind, and all of us would be destined for hell. Jesus will restore Peter after his sin of denying Christ and, by His death on the cross, will make it possible for all people to be forgiven for all their sin through faith in Him. In fact, Jesus will illustrate in the following verses the great lengths the Father will go to in order not to lose a single one of His little ones who have gone astray (Matthew 18:12–14).

Jesus is showing, though, that sin is the reason for the coming wrath of God. Those not forgiven for sin will face God's judgment in hell. Those who believe in Him must not tolerate giving in to the temptation to sin or, especially, leading anyone else into sinfulness. Jesus does not allow for any casualness about sin or its consequences.