When Government gets involved in marriage, it takes the power away from the citizen to determine their own conditions in marriage.
It is argued that Government need to set the rules for marriage, because otherwise then there will be no standard. But in the absence of the government making the marriage rules, the organisation that marries the individual, such as a church will make the rules, or allow the partners to do so.
Some examples of problems this causes
Lets take the classical divorce case.
From the mans side
From the womans side
Early ideas of marriage from the Anglo-Saxon period mainly treated marriage as a way of building relationships an strategic alliances.
1140: Marriage formalised by Gratian. Verbal consent was required.
1753: Marriage Act 1753 - Required a formal ceremony for marriage.
1670: Parliament passed an act allowing John Manners, Lord Roos, to divorce his wife, Lady Anne Pierpon
1836: Non-religious civil marriages allowed
1858: Legal process for divorce established -cruelty, desertion, bigamy, incest, sodomy or bestiality needs to be proved.
1969: Divorce Reform Act of 1969. Marital breakdown could be given as a reason
2005: Civil partnerships
http://www.bbc.co.uk/news/world-africa-19049000 premarital sex