Questions About Divorce and Marriage

What are the biblical grounds for divorce? This is the second part of the evening message with questions and answers. (It had to be cut in half because of the many questions.)

Among some of the issues briefly discussed are:
Did the Apostle Paul need to be married in order to write about marriage problems?
Should a cohabiting couple with children get married if one person becomes a Christian?
Fornication and adultery had different penalties under the Law.
The proof of virginity was evidence of the cutting of the marriage covenant.
What are the differences between legal separation and divorce?
What about the penalties for rape under the Law?
While we are not bound by the penalties of the Old Testament case laws, they do set forth lasting principles of equity.
The modern American way of dating and courtship is very dangerous and destructive.