Maybe the reason that religion works is this:
It is philosophically impossible to disprove something just because it has never been observed.
Of course, there is no reason to believe it either.
But then, our human nature seems strongly influenced by fear.
That is, even when there is no real reason to really believe in the existence of God, evolution has “programmed” us so that the mere possibility of the existence of a threat (hell) motivates us to avoid it, even if we may err on the side of too much safety.
It’s of course the same with politics. Even when there is no real 100% reliable proof of a certain threat, our nature has us prefer to err on the safe side and, although we may not deeply believe in the threat’s existence, we act to avoid it.
For instance, a friend may tell us about a really angry bear that is hiding in some cave. And although it may be the first time we hear of it and although it may never have been observed by us or anybody else, we will likely avoid going into that cave just to prove that there is no bear.
If somebody who appears rather weak tells you that he has a gun hidden in his bulky jacket or that he knows deadly martial arts tricks or that he has powerful friends or that he can sue us, we may not necessarily believe him, but neither does our disbelief outweigh our caution.
Which is where it goes back to evolution. My theory is that for survival of the human race, it is less important to avoid being lied to than to avoid dying because of distrust. E.g. if your parents tell you that a speeding car will kill you if it hits you, evolution has proven it useful for your survival to believe them – even if they may be wrong.
And of course, science can be used in the exact same way to manipulate you as religion.
When somebody tells you that science has proven that doing something is fatal, you tend to believe it, even if it may not be true. Again, here is an example of why this is useful: Let’s say science knows about an odorless and translucent liquid that will kill you from merely touching it. But it basically looks like water. Now you could either say “Nah nonsense” and touch it to prove “science” wrong. Or you prefer to believe “science”. You end up preferring safety, even if it comes at the cost of somebody being basically able to keep you from drinking perfectly fine water by claiming it’s toxic.
So in terms of evolution and survival, the cost of assuming a false claim of danger to be true is lower than the cost of assuming a true claim of danger to be false.
In turn, the amount of people with the predisposition to test claims of danger for validity (at the extreme end of the spectrum the psychopath?) is significantly lower than the amount of people with the predisposition to avoid danger over challenging these claims, because the former are much more likely to die from something that the latter would consider an “avoidable risk”. On the other hand, the latter are more likely to believe in risks that are not real and actually suffer a life much more intensely filled with anxiety and fear – but since they survive in greater quantity, they are the predominant predisposition of humans.
And that is my explanation of why religion, manipulation and fear works and prevails.