Exactly what the title says, Christianity in all its various strains still stems from the horrendous old testament, and with all the awful shit that endorses, as well as with things like Calvinism and the general doomsday cult foundations in the religion, why do some people still act so charitably towards it? Christianity has proven itself to be a morally corrupt and oppressive institution at every turn. Or maybe I'm just too negative? 
EDIT Ok guys I get it this was rather reductionist, and I definitely was disregarding all the good that religious folks have done, and that religion has inspired people to do, but again over correcting into enthusiastic support for religion can also be problematic.
People seek community and safety. We shouldn't let the forces of reaction pollute their minds with idiocy and hatred.