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?
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.

Jesus shows the unreasonableness of a man or woman finding fault with "a speck," or trifling thing in a some other Christian's eye, while he himself has "a log" or some large and formidable wickedness in his own life. To be an aid to someone else, one must deal with the dreadful wickedness in one's own heart first.