To read the texts click on the texts:1 Tim 1:1-2,12-14; Lk 6:39-42
The parable that begins this section is a rhetorical question. The blind who need someone else to lead them surely cannot lead another who is blind. What is worse is that if this is attempted both persons will be in trouble. This is why disciples who intend to lead others must first learn to be like the master. If they attempt to lead others without first learning from the master, their teaching will be erroneous.
The second parable reinforces the point made in 6:37-38 about not judging or condemning. Before one can point to the faults of others, introspection is called for. One must realise that often one might be guilty of greater misdeeds than the person to whom one is pointing.