One reason why you cannot control morals through legislature is that you have a very diverse population in any given country, yes there is a majority factor, but even then you have people of different factions to the majority who differ from them. Since some people have different Religions and some none at all, it is very hard for a government to dictate what is right and wrong, because in some issues it differs. Controversial subjects like abortion and execution bring up what people personally believe are right or wrong, and from person to person it differs. For a society based on freedom of religion, it’s hard to set a definite standard on morals.
Another reason that it is hard to legislate morality is that Society and its characteristics are always changing. It is very hard to make something into law if it is always changing. We Christians don’t follow the lord of Moses, and women aren’t stoned for adultery, And the acceptance of things then are different from modern times, and probably in another 5 decades, or outlook of right and wrong will change as we change. As Christians its hard to stay close to the pure morals as