Varanasi has been explained in Hindu religion as an ultimate place for liberation from cycle of life & birth. The numerous extracts from different Vedas, Upanishads & other religious texts explain this aspect of Varanasi with much vigour. It is believed that city is not important for human only but gods do wish to live here to get the ultimate liberation. So to understand here is ihe place from where everyone transcend from a door to the ultimate place of each identification. The truth is hard to understand in the context of generalization. But few enlightenments here by spiritual gurus in Varanasi put some light on it. One among the best spiritual Guru of India Swami Ramkrishna Paramhans felt while boating on river Ganga that Lord Shiva himself is enchanting Tarak Mantra in the ear of a laying body in the lap of Parvati. In Sanskrit word Tirth stands for a place where supernatural activities enlarge itself to be more intent. We see a kind of prevalent understanding that can't be put in any person on earth by just words or religion to understand that this is the place for ultimate salvation. People from around India come here to feel the same even people who don't have faith in religion  feel the same. Its a concept impossible more than a religious upheaval. In Hindu text each sin brings some punishment either small or harsh. No one can avoid the consequence of their sins, they will certainly be punished either in this life or another life. But dying in Varanasi is so pious that how much poisonous you are with your sins you will be liberated.