1. Socio-political control and gain. Religion can keep a population in line; it can deflect and suppress the hard questions and provide easy answers; it can sanctify and justify the activities of the elite.
2. An explanatory tool to understand the unknown and the confusing. Religion, not science, once explained the weather. Religion provides tools to understand the finitude of human existence. Religion quells the fear of death individuals experience once they become aware of their own mortality.
Religion accordingly fades into insignificance and ultimately death when it can no longer accomplish either of those purposes. History is littered with failed religions. Where are the Norse, Roman, or ancient Egyptian deities? They did not perish due to their followers determining that another religion was actually true; they perished because they were no longer the best explanatory tools the believers could utilise and because other religions offered greater potential for elites to achieve socio-political ends. Just note the conversion of European monarchs (and thus their people) to Christianity. Sure, some may have converted at least in part due to genuine motives, but by the time monarchs in Scandinavia and Poland were converting, there were clear political benefits to be gained by professing Christianity.
However, the past was largely a contest between the different explanatory tools and power potential of opposing religions. It was not a contest for religion itself. We are now in a situation where religion's explanatory tools and power potential are being called into more and more severe question by non-religious ideologies. Religion itself will die if it cannot offer the best explanation and if it ceases to serve the purposes of political elites. For if the people themselves do not accept the explanations offered by religion, and if political elites cannot use religion for control or gain due to its lack of acceptance, religion will no longer have a reason to exist, let alone provide any compelling reason for believers to offer their time, money, and deepest emotions.
How is religion being contested? In many ways, of which I shall list just three:
1. Scientifically. Serious academic debate has long since settled the evolution versus creation debate emphatically in favour of evolution. Creationism has been debunked as pitiful pseudo-science based on untenable claims that contradict the facts. Amongst well-educated societies, evolution has become the explanatory tool of choice to understand why we are here. It is a continual source of confusion to me as to why a considerable minority of Americans (including many intelligent and reasonable people) continue to accept creationism when the rest of the first world has thoroughly discarded it and only fringe religious extremists profess any belief in it.
2. Morality. Religions of sin and judgement are increasingly falling out of favour. I have a lot to write about this and it would be best saved for a future entry, so I shall limit my comment here. Traditional religious polemics on morality are increasingly falling out of favour as "sins" are re-examined. For instance, expressions of love are not sin. Ideas of fairness, equality, and justice are rising against traditional marginalisation and discrimination.
3. Politically. As church attendance and religious adherence plummet, religion ceases to be important to politicians. As democracy becomes the predominant political system and societies become increasingly tolerant of diversity and integrate different cultures instead of excluding them, appealling to one religion becomes detrimental as it excludes important voter groups that adhere to other belief systems. Religion no longer offers political elites any gains. Simply compare the high use of religion in the US political arena, where over 80% of the population is Christian (over 90% in some states), to New Zealand's political arena, where religious appeals are confined to fringe groups with little broad appeal to a society that is barely 50% Christian and has very low per capita church attendance (this in a country that was over 90% Christian a century ago!).
Religion is losing ground, in some places faster than others. The only territory where it maintains a monopoly is the supernatural, but if it cannot demonstrate the supernatural even exists (or if it cannot demonstrate that any existing supernatural realm actually tangibly impacts our lives through explanatory tools or power potential), then it is doomed to wither away and perish.
In much the same way as my Christian faith is withering away, really. It's been five years this month since my conversion in 2002. Will I reach a sixth year?