Q. Why are women more restricted about sex and marrying multiple men in the Bible? It seems women are 2nd class and held to different standards.
The Bible actually holds men and women to exactly the same standard regarding sex. It teaches that neither men nor women are to have sex outside of marriage. So in that sense, it does not restrict women more than it restricts men.
Regarding marriage itself, I discuss your concern at more length in this post: Is it a sin for a man to be married to more than one woman? The Old Testament speaks into a culture that practiced polygamy (more than one spouse) and specifically polygyny (men having more than one wife). The Bible regulates the practice in order to prevent abuses, for example, a less-favored wife being denied food, clothing, and the opportunity to have children.
However, it does not specifically approve of the practice. Rather, as I say in the post linked above, “At the very beginning of the Bible, God institutes marriage between the first man and the first woman and ordains that ‘the two be united into one.’ As the Bible continues, polygamy enters human history during the inexorable course of its drift away from God after the fall.” So while the Old Testament speaks into a situation of polygamy in order to ensure fairness within it, it is not explicitly giving men, but not women, the right to have more than one spouse.
The New Testament may actually restore the ideal of monogamy. According to one way of understanding the Greek text, it says that a male church leader must be “the husband of one wife,” presumably meaning not married to more than one woman. Another way to understand the Greek is “faithful to his wife,” but that seems to have similar implications.
So I think that the way the Old Testament regulates men having more than one wife while saying nothing about women having more than one husband reflects the characteristics of the culture into which it speaks. God encounters human cultures where they are and works within them to bring them towards his intentions. And personally I think that the Bible indicates that God’s intentions are for a man who is married to have one wife and for a woman who is married to have one husband.
Good Question 