There are often historic reasons for rules in religions. Some come out of self-interest (there's only one God -- don't fall for other religions and their habits), some out ofsome form of ethics which derive out of cultural background of the time (don't kill, have only one wife) and practical issues (don't eat pig -- without having a fridge and when being in Messopotamian heat pig meat goes bad quite quickly, leading to health problems, which can be put on God's will due to limited medical understanding)
The question is: Do the reasons still apply today?
The question is: Do the reasons still apply today?