It's not necessarily our religion that is the key. Christianity is a religion that historically contained the values/attributes that made for a successful society, but so have others through time. Rather than pinning it on a religion, define the attributes that we and other cultures in time have also had that made them successful.
Successful cultures are:
1. Time sensitive: Its hard to be militarily successful or complete complex economic tasks without a high degree of timeliness, the idea that one has to have something completed or be in a certain place and time to complete a task. Not all cultures are time sensitive. Even among European cultures the Mediterranean nations tend to be far less time sensitive than the Northern ones. Greece for example is very time insensitive. How can complex tasks in society be completed if merging events in time and space such as at a large construction project are near impossible because no one is where they are supposed to be, doing what they are supposed to be doing. The synchronization and coordination gets all out of whack in these cultures.
2. The willingness to use force: Cultures that rise and at least stay in power for a while have the “will” to take what they need or protect what they created. There will always be others out there that want what you have and if you're not willing to fight for it, they will simply take it from you. Rome got it's start that way. A bunch of farmers being ransacked occasionally they eventually got fed up and began arming themselves, protecting what they achieved through their labor.
3. Embrace technology/engineering/science/knowledge: Even if primitive by today's standards, this was true when comparing the ancients as well. Successful societies do not reject the idea of having machines, tools, new weapons, the skills in engineering and architecture improve their efficiency, lethality and effectiveness. Both in fighting and economically speaking, those cultures that embrace change and innovation are ones that thrive. Realize, that there are many cultures like the Amish out there that reject technology. Is a society as in many Muslim countries where women are regarded a pure breeding machines and not educated one that makes the most of it's human capital?
4. Rejection/acceptance of corruption: Societies with a high acceptance of corruption are doomed. These societies are generally operating with a low economic efficiency and all sorts of other issues. The Arab culture is very corrupt. They don't even see corruption for what it is!
Some nice examples (worth looking at):
http://www.transparency.org/policy_research/surveys_indices/cpi/2009/cpi_2009_table (Look at all the nations on top and all those on bottom)
The map view makes it very obvious what's happening here: http://fryeblog.blog.lib.mcmaster.ca/category/chart-of-the-day/
5. A common vision and cultural identity: Societies that are heterogeneous, a direction we've been heading in ever since we began embracing diversity (vs. assimilation) do not last, and are not successful in amassing wealth and power. They succumb to internal strife, sectarian differences etc. and are unable to to pull together in one direction simultaneously in times of need or even when it's economically beneficial because of economy of scale, risk mitigation etc.
6. The value of children and the institution of family: The basic building block of any society is CHILDREN. Have none, and you go extinct. Not a hard concept to understand, but many societies have gone under because of this: Sparta, Aztecs....... When you sacrifice 2% of your population per year (viable and healthy people), don't be surprised if after 20 - 30 years your civilization just sort of fizzles out of existence. Look at what is happening with Russia today? The Germans....... When you embrace this cult of death the results are long term very predictable. Societies that de facto reduce the family and no longer produce offspring are short lived.
7. A society that has a concept of personal culpability and self determinism in some form: Societies with a deterministic outlook on life are generally less successful. The Arab is a good example with his “Insha’Allah.” The Arab is not a Prussian soldier responsible for cleanliness and maintenance of his equipment. Some societies get so caught up in the after life, that they ignore the present. Some have a near fatalistic view and essentially stick their heads in the sand and there is no more personal accountability or even a concept of behavior/actions = outcome.
8. A value in output: Societies that value efficiency, precision, production are more successful. We would call this the “Protestant Work Ethic:” http://en.wikipedia.org/wiki/Protestant_work_ethic The idea that the widget maker that makes better widgets or builds more of them is worth more! The concept that their is value in labor, that it's ones duty to expend oneself to make as much and as well as possible: Think Rosie the Riveter. This is in stark contrast to the modern American liberal that wants to guarantee outcomes (education, health care, retirements.....etc) regardless of decisions and behaviors made.
There have been societies that are non Christian that were highly successful. While I am Christian and believe God, Jesus, what the Bible tells me, I also understand that there were other societies predating the new testament and thereafter that were successful without ever hearing the gospel: pre Christian/Constantine Rome, Egypt, some of the Chinese dynasties, in Japan.......... However, you will be hard pressed finding a successful society that lacks these attributes in mention. Often what happens is that a culture rises to power, looses the cultural traits that made them successful, and like the Greeks or Romans, fades into obscurity. Even though the Romans had adopted Christianity!
As an individual, your true degree of self determinism is limited and will vary from culture to culture, depending on how much freedom there is within it. However, while at the micro level you might have bad luck through illness, weather etc. and end up poor or ill even though working hard and doing the right things, at the macro level it appears that it is near entirely “culture” that defines success and failure. Cultures in austere resource depleted conditions STILL rose to power and amassed wealth when they adopt collectively certain traits. Literally, societies living in very harsh climates, with little resources, poor soil to grow things etc STILL managed to become wealthy and powerful, while some cultures with massive resources, fertile earth failed. Arguing that necessity is the mother of invention and that it is "because" of necessity that these cultures rose to power and prosperity is backwards and one can find many examples of cultures in resource rich and fertile soil that also rose to power. What did Germany and Japan have after WWII to catapult them to where they are today? Both are fairly resource depleted nations, yet both rose from the ashes like a phoenix.
It's culture that makes wealth, not wealth that makes culture. Mike Tyson is still who he is, even after making his millions, and he will most likely die poor as many of these people that rise to success that way do. German prisoner of war in WWII held in the US were afforded a large degree of movement and freedom in their activities. They weren't abused and we provided for them the essentials as required for POW’s. Their camps by the time the war ended had theaters, sit down cafeteria style eating lounges, they were growing additional vegetables to augment what they received as rations...... because they built that. They created the conditions they lived in and frankly they weren't that bad! They lived BETTER than the civilian in Germany having to live with food rationing etc.
Let's take a look at the Arab-Muslim world.
The bad: High acceptance of corruption, not very embracing of knowledge in reality (women are kept down, anything that contradicts their religion is suppressed........), very fatalistic/determinist in outlook, not very time sensitive for the most part.
The good: They will use force (not good for us when they see their interests and ours colliding), they have a collective identity, they have a concept of culpability and they breed quickly.
Here's another example of culture makes wealth, not vice versa:
http://www.thedigeratilife.com/blog/lottery-winners-go-broke-prospect-theory/
http://www.associatedcontent.com/article/70165/winning_the_lottery_curse_or_a_blessing.html
http://abcnews.go.com/2020/powerball-winner-cursed/story?id=3012631
Most people, that were in debt, behind in payments will be so again after a while even after they win the jackpot (even millions). Only those that had control of their finances and weren't living above their means before they won, actually hold onto and make something of their wealth long term. Culture makes wealth. Go into the American ghetto's, look around and you see broken houses, fences, walk ways......... How much money does it really take to buy a bucket of paint? You'll see people sitting on their bum, people hanging out.....but no one is painting, nailing, digging, sweeping, doing something that will make their surroundings better. They are all waiting for a miracle from the government or lottery.
You are correct that there are cultures superior to other cultures. You are wrong to divorce culture from Christianity. Further, it is not important to be successful, it is important to be right. It is the wrong in others that gives us a permission to fight war on them. Wars therefore are justly used to correct a wrong; the party that has not the Truth may not use force in order to be "successful", -- it lost already.
But truth is Jesus Christ. Truth is a person, -- that particular person. It is not a thing or a thought: it comes from the mouth of God Who makes it the truth.
It is possible, in the historical perspective, to be a reflection of some truths and be not Christian. Such were many societies of the Antiquity, that now perished. Today, some truths are presented in an un-Christian setting. So, a Muslim society can approximate justice because Islam is, after all, a Christian heresy. Pagan Japan can as well, because their spiritual intuition even without the light of the Gospel, has lead them to some universal truths.
Rome perished as a pagan creation that grew into Christianity. Medieval Europe -- I include Byzantium -- was Rome's successor, which perpetuated the best of Rome and placed it in the proper, Christian setting. While we don't like to see in ourselves an extension of Medieval Europe this is what we are: we exist coasting on the values of the Middle Ages. We better not lose them. If we do, it won't be another "more successful" society to replace us: anti-Christ will emerge, and then the history will end.
Our role is unique because we are charged with the lamp of Christianity. If we act as God told us to, we shall be successful and truth will be with us. If instead we act so that to survive better for our own sake, we shall lose as a society.
I think, America is entering a neo-Pagan period. The itch to get into wars is a sign of that. We better reform ourselves and soon.