Technically speaking here, society used to be based on orgy masses where ego simply did not exist; imagine a society where every woman was your wife, every man your brother, every child yours, and competition did not exist unless it was in sport. Everyone was "one" with another; that is the definition of love. That comes from the work of Terrence McKenna.
After the schrooms dried up, the dominator ego mentality came back. A society such as McKenna described cannot exist when you've got selfish people competing in it for resources they fundamentally do not need. Essentially, in a dominator relationship the man considers the children and women his property and does with them as he see's fit. He buys and sells them, abuses them, forces them to work, etc. This, on a large scale, is very bad; predation is self-destruction because predators produce nothing useful; a city of thieves produces no bread, and this kind of arrangement is predatory and keeps society from evolving.
Marriage was conceived as a way to construct society. Children were raised by individual monogamous families and were protected and educated by their parents. The monogamy kept the focus of the relationship on the children and kept social predators out of the loop so to speak. By passing on trades, land, and resources, those children would grow up to be strong, independent and free. Throughout the ages, no empire has been able to break that tradition; it has spread to every major world religion that exists today.
Humans are not naturally monogamous, neither is it natural to forget the ego and evolve beyond that. We're only monogamous because of several thousand years of the dominator mentality attempting to expand it's grip over every single thing it lays itself on. Marriage is nothing more than a defense mechanism and one I think, as technology obsolesces the dominator mentality itself, will become less and less necessary.
Now, you may all call me a fag and return to your inane rambling.
How come you only come out when I'm in the negative spotlight? 
