Jesus told a parable to his disciples: ‘Can one blind man guide another? Surely both will fall into a pit? The disciple is not superior to his teacher; the fully trained disciple will always be like his teacher. Why do you observe the splinter in your brother’s eye and never notice the plank in your own? How can you say to your brother, “Brother, let me take out the splinter that is in your eye,” when you cannot see the plank in your own? Hypocrite! Take the plank out of your own eye first, and then you will see clearly enough to take out the splinter that is in your brother’s eye.

‘There is no sound tree that produces rotten fruit, nor again a rotten tree that produces sound fruit. For every tree can be told by its own fruit: people do not pick figs from thorns, nor gather grapes from brambles. A good man draws what is good from the store of goodness in his heart; a bad man draws what is bad from the store of badness. For a man’s words flow out of what fills his heart.’