Divorce, and Jesus' comments on it
According to a sociological analysis I was reading, the differences between ancient marriages and modern ones are quite large.
Perhaps most importantly, marriages were commonly arranged by the respective families and the bride and groom would both have little say. The families would arrange marriages for political and economic benefit to themselves. In other words, what was important in the marriage was the relationship between the extended families, not the relationship between the individuals. A divorce correspondingly involved a rift between the families and not merely the couple themselves breaking up.
The analysis I was reading suggested that divorce was closely associated with feuds between families, a divorce being the splitting up of the two families. If done without sufficient warrent in public eyes, the termination of such a relationship would be dishonourable, and offensive, serving as a valid reason to begin a feud. The purpose of many ancient regulations (including the ten commandments) was to prevent feuding between families and thus maintain a stable society. The analysis therefore suggested that a prevention of feuding was upmost in Jesus' mind when he taught against divorce.
It should be noted that adultery in the ancient world was a bit different to what we would now consider it to be. Only men had "honour", women didn't count on the honour scale. To commit adultery was to dishonour another man by taking what was his - ie his wife. A man by definition could not commit adultery against his own wife - the wife didn't have any honour that could be undermined. So if a married man went out and slept with as many prostitutes as he felt like, that was not adultery (and indeed was generally considered okay). Hence a man could divorce his wife for adultery (dishonouring him by letting another man sleep with her), but a woman couldn't divorce a man for adultery because a woman had no honour to be undermined. If a man committed adultery it would be against another man, by sleeping with that man's wife.
With the extended families involved, adultery gets even more complicated. By being party to adultery, the woman is (as a representative of her extended family) bringing dishonour to the man and his extended family. Such dishonour would be cause for the offended family to justly break off the relationship.
Jesus on the subject
So when Jesus forbid divorce except in cases of adultery, why was he saying it? Unless we know why he was saying what he said, we cannot tell whether his prohibition applies to us equally. Which part of the ancient marriage/divorce system was he commenting on, and why? And if we have that part in our culture today, is the same criticism still valid for the same reasons? It might be that Jesus' reasons for saying what he said would not apply in our culture. It might be that what he commanded would conincidentally still be correct in our culture but for totally different reasons to why he said it then.
Some Christians today are totally against divorce due to Jesus' comments. Others take Jesus' words as a nice ideal, because they see that divorces can be painful for both parties and especially for children involved, but they realise that a couple being forced to stay together could be even worse. Other Christians just say "divorce is fine, people are entitled to get divorced if they feel like, what's the fuss about?" So what ought to be the "Christian" attitude to divorce?
It seems to me that the "What Jesus said about divorce applies to us" argument is totally worthless unless it can be backed up by a careful study of exactly what led Jesus to say what he said, and how it is valid to apply this to our culture. For example, if Jesus said what he said because he was concerned about dishonour leading to family feuding then it has little direct relevance to our culture.
A lot of Christians think they can use the Bible as a timeless moral textbook, and import statements directly into our culture out of the one they came from. I find this scary. They are effectively saying that group of cultures 2000-3000 years ago (in which the Bible was written) are to be the authoritative judge of our culture now and all cultures still to come. At best that is pretty unenlightened, at worst downright terrible given some of those cultures sanctioned genocide.