Luke 6: 39 - 42
39 He also told them a parable: "Can a blind man lead a blind man? Will they not both fall into a pit?
40 A disciple is not above his teacher, but every one when he is fully taught will be like his teacher.
41 Why do you see the speck that is in your brother's eye, but do not notice the log that is in your own eye?
42 Or how can you say to your brother, `Brother, let me take out the speck that is in your eye,' when you yourself do not see the log that is in your own eye? You hypocrite, first take the log out of your own eye, and then you will see clearly to take out the speck that is in your brother's eye.

EWTN