The key phrase in jgardin
's writeup above is "those that should be obeyed". This implies that there is such a thing as a legitimate power structure
in which it is right
for some to have power
Accepting this premise necessarily begs the question of from where authority derives and what exactly constitutes its legitimacy.
This question has been answered in many ways over the millennia. Some of the most popular answers have been:
The Mandate of Heaven - the idea that the gods/God/supernatural entities have chosen a particular person or group of people to be set above others. The supposed will of these entities being paramount, people have no correct choice other than to obey their rulers and, by extension, their supernatural superiors. This is also manifested as the divine right of kings.
The Will of the People - The theoretical basis for democracy; the concept that "the people" (the society, the community, the body politic) choose to surrender a measure of their personal power to the community at large via the agency of the state and the elected representatives which constitute the state. An outgrowth of the ideas expressed in Rousseau's Social Contract. An individual in an "enlightened", rationalist society obeys his/her rulers because he/she feels that the rulers' authority derives from the will of the people.
In our day and age, the latter of the above two legitimizing philosophies is considered to be more correct, rational and acceptable than the former.
However, the first philosophy cuts closer to the true source of authority and the basic reason for obedience to it: violence.
Authority = power, and power = a superior ability to inflict violence, regardless of what form the violence takes (physical, economic, emotional, psychological, etc.). At heart all systems of authority, all power structures devolve into that old adage: might makes right. Even the most democratic of states operates on the principle of the will of the majority: there are more of us than there are of you, so do what we say.
The feeling that power must be obeyed stems, probably, from the parent-child relationship. As children, we are compelled to submit to the will of our much more powerful parents. We are inculturated to bow to the greater force.
And so we have a society based obediance to authority. We've even whipped up the collective myth that there must be power structures, or there would simply be chaos (again, fear of violence). This ignores the massive human potential for mutual respect and mutual aid. A society based on cooperation is entirely possible and, considering what our current social organization has inflicted upon the world, entirely necessary for the survival of the species.
Obediance is the result of internalizing the idea that might makes right. Might does not equal right; might simply equals might. The mighty are nothing without those willing to submit.