Up until the Enlightenment, religion and government were virtually the same thing. At a basic level, kings or emperors justified their rule by divine mandate, while clergy relied on the patronage of the government to prosper and survive. Religion evolved from disorganised superstition and the government evolved from disorganised banditry, but they were both born together about six thousand years ago in Ur, present-day Iraq, together with the first writing, and "civilisation" in general. It was writing that made organised religion, government and empire possible, among other things. If one looks at the 1st and 2nd-generation empires that emerged in the Middle East in ancient times, it is obvious that the imperial state was derived from a religious belief. Ancient Egypt is another obvious example of the head-of-state literally being god on Earth.
Assuming we're talking about European history, this is false. For a large proportion of population religion was largely unimportant up to the start of the Christian era. They needed to placate their gods, pray to them, give them offerings, but since there was no universal religion, there was also no reason for a king or emperor to claim divine right to rule.
This did come later, with Christianity, but even there the Church and the State were separate, and quite often struggled for power, especially in the west. The fact kings claimed a divine mandate hardly ensured their loyalty to the Church, many weren't exactly pious at all.
Ancient Egypt is a somewhat special case in that the Pharaoh was worshiped as a god. This was also the case with pre-christian Rome for a few decades starting with Diocletian, but the religion was largely unimportant to the decisions made by the state at that time, for reasons described.
In Islam, the Church (as in organized religion) and State are intended to be inseparable entities, and we can all see how well that works (i.e. not at all).
I'm sure we're all aware that the classical democracies in Greece and Rome were heavily informed by superstitious belief. It was only in the 18th Century, really, that some governments became secular with the advent of modern democracy - the United States of America being the obvious example.
That would depend by what you'd mean with "secular". If it's that the religious authority doesn't play a significant role in decision-making, this predated the modern era. In Byzantine empire, for instance, the church served the state. It wasn't a secular government, but the church was a servant of the state - hardly a religiously governed state by any standard. Russia borrowed this and much more from Byzantines.
From an honest, skeptical perspective, the Protestant Reformation is not sufficient an alleviation of dogma, is it? Sure, the corrupt and evil Catholic clergy aren't in control any more, but where are we two hundred years later? Look at the state of Protestantism in America, and tell me it isn't corrupt, absolutist and intolerant. Look at the government and tell me the same thing, for that matter.
The US government isn't absolutist and intolerant if you use any meaningful definition of the two, but you have a case about it being corrupt.
The difficulty with religion - no matter how much you tone it down and try to make it friendly - is that it rests upon a false premise: that god exists. The government suffers from a very similar difficulty, but it sounds glib and inane if you phrase it in the same way. The state doesn't exist, but what this means in the context of politics is that there's really no justification for state coercion... War, taxation, conscription, imprisonment, prohibition etc.
The state exists in the same way friendship exists. It's been a very long time since we mastered abstract thought. You probably missed the last couple dozen thousand years, brush up on that will you?
Now this is where the monkey poo usually starts flying.
As far as I'm concerned it already made a few barrel rolls and dives and it's going for a speed record in level flight right now.
You see... The reward for following a religion comes in the next life,
This depends on religion.
but a secular state has to provide perceived rewards to its constituents. Look at any pro-state ideology from libertarianism to communism, and they all want the state to provide them with something. The libertarian thinks that only the government can provide roads and national defence, or whatever, while the communist has been completely enraptured and thinks the government is the source of all productivity, but either way... They have this belief that there are certain fundamental things, essential to their way of life, that only the government can conceivably provide, and that's why it's a necessary evil at the very least and an omnipotent provider at best.
Human beings tend to do things that benefit them, and avoid things that harm them. Smart, no? Obviously it's not always as simple since most issues have both good and bad sides to them, but generally speaking humans tend to support things that they perceive as more beneficial.
From an economic perspective, there is nothing the government "provides" that could not be provided by the market to most and charity to those in genuine need.
You're telling me you could pay for a police force through charity? Let's see some calculations on that, shall we?
I'm not saying it would be a hundred percent perfect, but it WOULD be a damned-side better than the current situation. All you have to do is recognise the simple fact that the government has no more wealth than the individual members of society - it has a monopoly on the money-printing machine, sure, and it has the power to condemn your children and great-grandchildren to perpetual debt, sure, but that does not generate wealth!
It certainly doesn't generate wealth, but it's a lot better than having no oversight at all at which departments of society are in need of resources and which are not.
McHrozni