John Burnett
(These are just some raw notes, to which i plan to add from time to time.)
Marriage in our society today is not what it was in first century Palestine, or (this is what opened my eyes) in 21st century rural Africa (where it turns out, life is still very similar to that of first-century palestinian peasant-agrarian society).
Marriage in developed Western societies today is a private, voluntary contract undertaken by two independent, private, individual consumers of either or both sexes with a view to romantic/erotic love and companionship. The individuals choose the extent to which they will retain or commingle some or all of their separate assets. The actual wedding may be conducted in private or in public, although like many legal contracts, by law it must be witnessed by a third party who may or may not be a complete stranger, and it must be in any case certified by the state. A religious framework is entirely optional. Getting married may or may not involve a decision to produce offspring, and lack of offspring is not automatically grounds for annulment or divorce. The rights and responsibilities of the marriage partners, while largely a matter of mutual choice, are ultimately regulated and, if necessary, adjudicated by the state. Marriage has significant tax implications, which may even serve as the primary basis for the decision to marry or not. In general, marriage today is entirely a matter of personal choice, terminable at will, without cause, and without fault by either party. If there are offspring, both parents remain legally responsible.
Marriage as discussed in the Bible and in the canons of the Church, and practiced in places like traditional africa today, is a more or less mandatory union of two persons of opposite sex* who are significantly embedded in their respective clans. In peasant-agrarian contexts, marriage is very importantly tied to land-tenure. Marriage is often arranged by the families and sometimes imposed on the parties. It is often undertaken for purposes of social and economic advancement, and marriages that might lead to loss of status are often refused, regardless of how "right" they may seem otherwise.
Clan recognition is absolutely necessary in the biblical and traditional context. Securing the clans' mutual permission and recognition mandatorily involves a substantial exchange of traditionally prescribed gifts and payments (the dowry, from the girl or her family to the boy or his family; or the bride-price, from the boy or his family to the girl or her family). Since land tends to be held not by individuals but at the clan level in traditional societies, redistribution and inheritance in the event of marriage or divorce are regulated by strict customary arrangements which can differ from tribe to tribe. The wedding, a highly formal affair, simply cannot be conducted in private because it is really about two entire clans' acceptance of each other into partnership; it must therefore be witnessed by both entire clans.
The primary purpose of the union is to produce offspring. Infertility or simply the non-production of offspring is grounds for divorce.
Traditionally, clan and tribal life provided the mandatory and inescapable religious framework, and although western missionary Christianity has introduced complications into this, it remains surprisingly resilient. The marriage partners' rights and responsibilities are regulated by explicit tradition and custom, and are adjudicated not by an abstract state but by clan elders who are usually very close to the parties and who rely on such custom and tradition. Traditional marriage are terminable, but upon termination the bride-price or dowry must be repaid. Divorce is a divorce of clans as well as of individuals. If there are offspring, they may be and often are repudiated by the parent with whom they do not live.
As anyone can see, there are extremely significant differences between our experience today and that which is assumed in the Bible. It is simply not possible, then, to apply biblical statements about marriage, divorce, or related matters directly to the modern context; there is always a need to reflect on the meta-values expressed in the biblical particulars and to determine whether they have any application within the present context.
*some tribes historically have accommodated same-sex arrangements, although under customary frameworks that varied from open to secretive.
For further reading about adultery and divorce in the Bible, see this pdf on the passages in the Sermon on the Mount (Mt 5.27-32) which form the basis of the Church's canons regarding marriage and divorce.