Luke 17:1-3

And he said unto his disciples, It is impossible but that occasions of stumbling should come; but woe unto him, through whom they come! It were well for him if a millstone were hanged about his neck, and he were thrown into the sea, rather than that he should cause one of these little ones to stumble. Take heed to yourselves: if thy brother sin, rebuke him; and if he repent, forgive him.