correct oneself before criticizing others
—Before the politicians tell us how we need to stop spending money we don’t have, they need to remove the beams from their own eyes.

Jesus warned the people against judging others without first considering one’s own faults, especially when one’s faults are large like planks (“beams”) and theirs are small like specks. The message is this: people first need to take care of their own sins, then they can help others with theirs:

Why do you see the speck in your brother’s eye, but fail to see the beam of wood in your own? Or how can you say to your brother, ‘Let me remove the speck from your eye,’ while there is a beam in your own? You hypocrite! First remove the beam from your own eye [cast out the beam out of thine own eye], and then you can see clearly to remove the speck from your brother’s eye. (Matthew 7:3-5)