Matthew 18:6-9
6 but whoever causes one of these little ones who believe in Me to stumble and sin [by leading him away from My teaching], it would be better for him to have a heavy millstone [as large as one turned by a donkey] hung around his neck and to be drowned in the depth of the sea. 7 “Woe (judgment is coming) to the world because of stumbling blocks and temptations to sin! It is inevitable that stumbling blocks come; but woe to the person on whose account or through whom the stumbling block comes! 8 “If your hand or your foot causes you to stumble and sin, cut it off and throw it away from you [that is, remove yourself from the source of temptation]; it is better for you to enter life crippled or lame, than to have two hands or two feet and be thrown into everlasting fire. 9 If your eye causes you to stumble and sin, pluck it out and throw it away from you [that is, remove yourself from the source of temptation]; it is better for you to enter life with only one eye, than to have two eyes and be thrown into the fiery hell.
Mark 9:42-50
42 “But whoever causes one of these little ones who believe and trust in Me to stumble [that is, to sin or lose faith], it would be better for him if a heavy millstone [one requiring a donkey’s strength to turn it] were hung around his neck and he were thrown into the sea. 43 If your hand causes you to stumble and sin, cut it off [that is, remove yourself from the source of temptation]! It is better for you to enter life crippled, than to have two hands and go into hell, into the unquenchable fire, 44 [where their worm does not die, and the fire is not put out.]
45 If your foot causes you to stumble and sin, cut it off [that is, remove yourself from the source of temptation]! It would be better for you to enter life lame than to have two feet and be thrown into hell, 46 [where their worm does not die, and the fire is not put out.]
47 If your eye causes you to stumble and sin, throw it out [that is, remove yourself from the source of temptation]! It would be better for you to enter the kingdom of God with one eye, than to have two eyes and be thrown into hell, 48 where their worm [that feeds on the dead] does not die, and the fire is not put out.