We are manipulated by those who know the power of belief

The power of faith, aka belief, is the most powerful force to be reckoned with on earth, among people. Divide and conquer and unite and conquer are two sides of a single coin.
The most important thing is that a person or people is steadfast and unwavering in what they believe.

In ancient Babylon, the people were of one mind, united in purpose (Gen. 11). That's what empowers a person or a nation to achieve great things. "If as one people speaking the same language they have begun to do this [build the city and tower], then nothing they plan to do will be impossible for them." (:6)
Control what people believe and control the people.
Faith/belief is the same power that enables advertisers to sell us their wares, bankers to sell us credit, and stock market manipulators to generate consumer confidence (faith), and medicine to sell us their cures, regardless of all the potential side-effects. They need only create the desire for something, or the belief we need their product, then give us the way to get them.

"If you can?," said Jesus, "Everything is possible for him who believes." (Mark 9:23) Even moving mountains, He said in Matt. 17:20-21.

The powers that be know this. It's why the American Civil War was necessary to unify the states into a single nation. It's why this same war-weary but divided nation had to be coerceded into believing there was a legitimate threat to our continued existence, to achieve unity of purpose in declaring yet another war on Iraq and terrorism. And the same tactic of belief-manipulation will be used to get this more-war-weary nation to take up arms in future wars. And they'll try to make us believe it's all in our best interest, of course.

Belief is the key. Believe something yourself, and you can do it. Make someone else believe something and you can get them to do anything you want them to do.

"...he who doubts is like a wave of the sea, blown and tossed by the wind. ... he is a double-minded man, unstable in all he does." (James 1:6-9) But be fully convinced in a matter and you have the power of one mind, one heart, one cause or spirit -- for good or ill.