This is impossible unless your skin is really thick. Unlike most cases, skins don't have any built-in structure to distribute the shock of the impact. If the phone hits a corner, even with a skin on, the shock will be localized on that area alone, putting an enormous amount of pressure on a tiny area. This is what causes metal to deform or glass to shatter.
Of course, if the skin was very thick, it would act as a cushion to slowly decelerate the phone, but then it would look ridiculous. Like a sumo suit for your phone. You need a case for shock protection.