"When faults in others misguide and delude you – have patience, introspect, find faults in yourself. Know that others cannot harm you unless you harm yourself." - Srila Bhakti Siddhanta Saraswati Thakur
One time when Jesus was in Jerusalem, he saw some people chasing a prostitute and trying to stone her to death. When Jesus stopped them and asked them why they were doing so. They replied that it is mentioned in the laws of the scriptures that one who commits adultery must be stoned to death. They said that they had caught her red handed and were just following the law. When they asked Jesus his opinion he replied, "Yes, you can very much stone this lady to death but one who hasn't sinned in his life can cast the stone on her." One by one, everyone put down the stone in their hands and quietly walked away. This lady fell at the feet of Jesus and surrendered to him. Jesus told this lady to not commit sin again and walked away.
The compassion of Jesus and his vision of seeing the tiny spark of good in her, transformed her heart. Everyone being a part of the All-good Lord are inherently good but are now covered with bad due to prolonged association with the material world. And just like Jesus Christ, everyone needs someone who can see the spark of good in them and fan it till it becomes a blazing fire which will burn away all one's bad. We should always keep in mind that every saint has a past and every sinner has a future. No one's destiny is etched in stone, it can change for good if someone just believes in their goodness and is willing to encourage them in this journey of transformation.
Another interesting point is that these people who were pelting stones on this lady thought that they were following the word of the scripture but they completely forgot to follow the spirit behind the words and thus they needed a wise teacher who lives the scripture to remind them of the spirit of the scriptures. Very often in life, instead of following the example of Jesus and being broad-minded, we start to follow the example of these narrow-minded people who were casting stones and become ever eager to cast the stones of our judgement on others calling them ill names and criticising them. In the excitement of finding faults, labeling them and advertising them we completely overlook our faults and our misgivings. What a sad plight. We call others bad as if we are very good.
Srila Bhakti Siddhanta Saraswati Thakur, a great spiritual teacher of the Gaudiya Vaishnava line gave the example of a sieve which is used to strain away coarser particles from finer particles pointing fingers at a needle and criticising it for having a hole while completely forgetting the fact that it has thousands of holes. That is our position. He would say that if we really want to find faults, we can find them in ourselves, there will be enough subject matter to keep us occupied for a lifetime.
Once Mother Teresa was asked, "What is the biggest problem in this world?". She instantly replied that "the biggest problem in this world is that I am a sinner." What an amazing answer. The biggest problem in the world is not that "others are sinners" or that "there are so many sinners out there" but that "there is a big sinner in here, in our very heart". How wonderful this world would be if everyone thought themselves to be the biggest sinner and focused on improving and rectifying themselves rather than looking for someone to put the blame on.
Srila Prabhupada, the Founder Acharya of ISKCON always gave the example of the difference between the bee mindset and the fly mindset. A fly goes searching for one piece of filth even in the cleanest of clean place and a bee goes searching for one fragrant flower even in the filthiest of filthy place. Who are we going to be like - a bee or a fly? Fault finding is an addiction like any other addiction, in fact it's more addicting than other addictions and more detrimental than others too. And the only way to overcome this addiction of fault finding is by seeing the fault of finding fault and consciously replacing it with the habit of finding good.