This lesson from the Buddha has been a powerful factor in my life. Whatever you focus on in life becomes your story. Following are a few other quotes and stories that illustrate this idea.
DON’T JUDGE, LEST YOU BE JUDGED (source)
Luke 6:37-42  “Do not judge, and you will not be judged. Do not condemn, and you will not be condemned. Forgive, and you will be forgiven.  Give, and it will be given to you. A good measure, pressed down, shaken together and running over, will be poured into your lap. For with the measure you use, it will be measured to you.”  He also told them this parable: “Can a blind man lead a blind man? Will they not both fall into a pit?  A student is not above his teacher, but everyone who is fully trained will be like his teacher.  “Why do you look at the speck of sawdust in your brother’s eye and pay no attention to the plank in your own eye?  How can you say to your brother, `Brother, let me take the speck out of your eye,’ when you yourself fail to see the plank in your own eye? You hypocrite, first take the plank out of your eye, and then you will see clearly to remove the speck from your brother’s eye.
Swami Vivekananda (source)
Thought is all important for “what we think we become.” There was once a Sannyasin, a holy man, who sat under a tree and taught the people. He drank milk, and ate only fruit, and made endless ‘Pranayamas,’ and felt himself to be very holy. In the same village lived an evil woman. Every day the Sannyasin went and warned her that her wickedness would lead her to hell. The poor woman, unable to change her method of life which was her only means of livelihood, was still much moved by the terrible future depicted by the Sannyasin. She wept and prayed to the Lord, begging Him to forgive her because she could not help herself.
By and by both the holy man and the evil woman died. The angels came and bore her to heaven, while the demons claimed the soul of the Sannyasin. “Why is this!” he exclaimed, “have I not lived a most holy life, and preached holiness to everybody? Why should I be taken to hell while this wicked woman is taken to heaven?” “Because,” answered the demons, “while she was forced to commit unholy acts, her mind was always fixed on the Lord and she sought deliverance, which has now come to her. But you, on the contrary, while you performed only holy acts, had your mind always fixed on the wickedness of others. You saw only of sin, and thought only of sin, so now you have to go to that place where only sin is.” The moral of the story is obvious: The outer life avails little. The heart must be pure and the pure heartsees only good, never evil. We should never try to be guardians of mankind, or to stand on a pedestal as saints reforming sinners. Let us rather purify ourselves and the result must be that in so doing we shall help others.