I think at a minimum anyone who wants to be a well rounded educated adult familiar with western literature should read through some of the best known parts of the bible. Things like Genesis, Job, the psalms, and the four gospels. If you care at all about western literature and philosophy you can't completely understand authors such as Nietzsche, Tolstoy, Dostoevsky, Melville, Dante, and many other without understanding the bible. As for why the bible vs. other religious texts, well I think trying to read the Koran and Lau Tzu's Tau Te Ching are worth the effort as well However, I think it makes sense for a western person to read at least parts of the bible first because, like it or not, the bible was so much more significant in shaping western literature and culture than any other book.