Does a Jew have to marry another Jew or can they marry a non-Jew... What happens if they do marry a non-Jew?

Answer 1

People from observant Jewish communities would be under strong pressure to marry inside their own community (the same way most Hindu families expect their children to marry a Hindu of the same community). However, nothing "happens" if a Jew marries a non-Jew. (Not sure what you're implying. Lightning doesn't strike and they don't get beheaded.) The Jewish partner does not get excommunicated and can still be Jewish. If the couple want to raise their children as Jews, then they can do so if it's the mother who is Jewish. If the mother is not Jewish, then she may have to convert, or the child may have to convert, in order to be considered a Jew and be able to worship as a Jew. However, Reform Judaism accepts children of non-Jewish mothers as Jews if the father is Jewish.