Implications of a Global Secular Government

Secular Humanist politics follow that, since the world is one single ecosystem of which humans are merely one part, we should form government as a single unit as well. Thus, Secular Humanists tend to favor the idea of global secular government, which would essentially make the world like one "country." The implications that a secular world government would aim to have would be to eliminate religion and war, and establish "peace." Secular Humanists believe peace is attainable as the process of evolution continues due to a.) the progressive nature of evolution and b.) the innately good nature of mankind. However, according to the Second Law of Thermodynamics, this world is in a constant state of entropy. Things are getting progressively worse, not better. Therefore, if peace was not attainable in the past, why would it be more likely in the future (that is, if we apply the digression of the natural world to the affairs of man, as a Naturalist worldview does)? Secondly, geographic differences/separation and different histories/cultural backgrounds would make a world unification, and thus, a single-nation world, impossible. As a result, the elimination of warfare would be unachievable. As long as mankind is not totally in agreement with one another, there will be argument-- there will be something to fight over, and therefore there will be war.
Ironically, therefore, a secular world government would (by the very nature of humanity and the world) be unable to achieve its very purpose or goal. In contrast to this Secular Humanist view, Christianity suggests that government is instituted by God to maintain justice, freedom, and order in a chaotic world filled with people who, by their very nature, are predisposed to mess it up! In the Christian worldview, the purpose of government is clearly defined in the Bible as such, which contrasts it from the Secular Humanist philosophy, which is based on the thoughts of modern-day Secular Humanists, rather than (as Christians accept) divine inspiration. Because God has this authority over the government, Christians often claimthat a government's power should remain quite limited, an idea contradictory to the "global power" concept of Secular Humanism.