Judaism isn't much of a "this way or no way" religion. Life and death is a valid out for anything, so if your house is burning, you can put it out. This is what the Mishnah is all about. Someone comes along with a new situation and wants to know the rules, so the rabbis and the ravs all debate, based on past precedent and extrapolation, and come up with an answer. Someone asked if lobster was kosher, and after due consideration it was pronounced to be trayf as it had a split or cloven "hoof". When phones were invented, the had to decide on the rules for that. But basically, beyond the basic rules (10 cmdmts) ( and we have different ones than christians) its common sense. Also, we don't stone people for breaking the rules anymore ;-).