Major issue: Christian ethics aren't stable. Polygamy, genocide, and slavery were all perfectly normal parts of life at various times during the development of the modern Christian faith. Those practices are frowned upon currently, at least in polite company. While many Christian ideas have in some way shaped current moral beliefs, their direct influence is much smaller than it is usually given credit for. And consider the CEV proposal. Early Christians thought that women and individuals of other races were not nearly as morally important as the males in their culture, but intelligent early Christians probably would have found the idea of gender and racial equality weird and moderately disconcerting, but not terrible. It might perhaps be analogous to if I told you that a few centuries from now, it would be regarded as a horrible, immoral belief to hold that a human's life was any more important than a Chimpanzee's (ie Trolley problems with two chimpanzees vs one human). That idea is weird and semi-disturbing, but it doesn't seem terrible. Drift of your moral feelings is fine. Just make sure you put some thought into what sort of direction you want your drift to be in.