Everyone of course may have different answers to this question but maybe not so many people have actually thought about it at all.

The interesting thing about this question is that most people regardless of their faith will find the real answer is the same.

Let me begin by saying something all intelligent people can agree is a fact, and that is there are hundreds of different religions practiced around the world. In fact,if you break down "religions" into sects or versions, there are thousands. Scholars estimate there are 30,000 different versions of Christianity alone(I was a bit shocked at that number myself). Islam, Hinduism, Buddhism etc., all have varying versions or sects that comprise the various beliefs across the planet.

If I ask a Christian why they believe it might be something like this, "His word is preserved and the Bible says this or that..".
A Muslim might have a similar response like, "The Profit Mohammad says in the Quran this or that..". And so down the line of beliefs it goes.

All of them would be wrong of course. Because these answers only espouse WHAT they believe, not WHY they believe.

Although there are exceptions to every rule, for example, people who convert from one faith to another. It may seem this happens often, it is actually a very tiny percentage in relation to the global population.
With the advent of modern science and technology like micro-biology, astrophysics and planetary sciences to name a few, some have digressed from religion to a more agnostic or atheistic view.But again these represent a very small portion of the world population.

So for the majority of the population, why do they believe what they believe?

The surprising and simple answer is: Geography!

To make my point, If I took an avid, devout Christian from the Bible belt who recites biblical verses here on this site and went back in time a hundred years or so where his grandparents, parents and themselves were born and raised in India instead of say Georgia, They would most likely be a Muslim, Buddhist or Hindu now rather than a Christian.

This is true not just in global or country regions, but also in smaller degrees like states, cities and towns.

You would be less likely to be a Mormon if you were born and raised in Tennessee then in Utah.

So there are two things to ponder here.

1) The first is that it is impossible for all the religions and beliefs to be "the right one".
Which leaves the possibility that none of them are "the right one".

2) Secondly, and probably the hardest pill for some to swallow here is: Your faith and what you believe is based more on geography than any truth or reality!

I think it was Rene Descartes who wrote: "I think therefore I am"

Following that and to tremendously simplify the answer is: people generally do not think independently - they follow. This regardless of geography.

But what or who they "follow" is based on where they are.

I don't see the need to believe in any kind of god... organized religion is just a scam, so I just follow my own personal morals

I get that and respect that(I also feel that way)..maybe one of the exceptions I mentioned but this thread was more about those that "believe in a religion". That is why I posted it in Religion Chat.

Whatever happens to different lives and different religions, the truth will always be there. To believe is to live.

Interesting topic, many will take offense at but interesting all the same.

While I find accuracy in your suggestion it doesn't explain the belief reasons completely.
While location has something to do with it, there's more, much more.

Some of it can be accounted to tradition and family acceptance.
Some to community acceptance and how your particular society functions in unity.
A lot of it has to do with life experiences and expectations.
Knowledge, intelligence and wisdom.

Religion is a unifying condition of society.

I believe in God but the God I believe in does not exist in any religion.
Some might say that invalidates my belief but since its my belief, it doesn't matter what others think.

My belief of my God fits how I understand the condition of existing in the Universe. It makes sense to me. I find comfort and contentment in it.
People believe what they believe because it makes sense to them.
It provides them with comfort and contentment in their existence (I hope).
Religions provide a baseline for common belief and the person uses that baseline to form their own beliefs.

There are not 10s of thousands of beliefs, there are 7.5 billion beliefs because everyone has a different belief and while some may have similar beliefs, no two beliefs are the same. When I say God, you think of the God you believe in (if any at all), not mine.

Religion is a social order to provide unity in a given society.
It uses rewards and punishments to change behavior patterns in their societies. It sets up a common pattern for people to follow on how to think and act in unity with each other. Common to the religion that most closely follows their individual beliefs.

The goal of any religion is to convince all people on the planet to follow their established version of belief. To create a world unity of society based on that particular religion.
Many of the religions started with a closed group.
It encompassed location by region.
Many did not even know of other religions in the world because to them, in their location, that religion was the only one.

As communication became more common between different regions and regions of different religious beliefs were suddenly visible, a conflict arose in the view of religious 'world unity'. Wars erupted, new religions formed that used parts of different religions to explain people's belief. Location stopped being the isolator.

Now, we have higher common knowledge. Some religious doctrine doesn't make sense to our beliefs anymore. People lose faith in one religion and seek out one that fits their own personal beliefs. When that is not found, some give up on religion altogether, some, like myself, adopt their own beliefs outside religion.

We live in a constantly changing Universe. Religion asks you to ignore that. Which makes no sense because anyone can see the constant change.
For me, religion makes no sense. However, if someone gets comfort from religion, I don't see why that has to be a problem for me.

When you are born you are taught a language.. little by little over time. This language you take as the way it is supposed to be. you communicate with it, are comfortable with it and everyone around you speaks it. It becomes the rule

With religion, it is no different, you are taught what to believe from a very early age. Your family was taught it, they live it, most of your friends live it to.. it becomes the rule.

Now if you continue believing in your adult years is a different story but the core of those teaching will always be in you.

Organized religion does what it is supposed to do.
It controls people.
The system of rewards and punishments is a very effective control mechanism.
Couple that with people's fear of dying and you have a extremely effective society control mechanism that requires you to die to know if it is true.
Its power is in the phrase "What if they're right?".

I find that my belief in God has a little to do with my Christian upbringing but has more to do with how I understand the Universe and how things are in reality.
The more I think about God the more it changes from my baseline Christian source and the more it make sense to me. So the longer I think on it, the stronger my belief gets.

It fits the concept of Christianity but it also fits what I understand about the science of reality. I'm no longer being judged and on trial for being alive. My God isn't a jealous God, as a matter of fact, my God takes no part in me more than anything else in the Universe. God is part of me and I am part of God. We are not separate things.

Some I have talked with try to tell me I am Buddhist. I have no idea what Buddhist is? I may have some similar beliefs but I also have many different beliefs. I don't believe life is sacred. Life is just life, you either are or you are not alive. I don't believe in reincarnation. I am who and what I am because that is the signature of my atoms. When that signature is gone, so am I.
The energy that is me, exists in the Universe, right now, confined to my atomic pattern but it will be released to merge with all the energy in the Universe when I die. Think about how big I am and how big the Entire Universe is. I won't exist as I am now. My energy will. Everywhere.

People believe “what” they believe based on life experiences. Their perception is altered by many different factors including geography., parents upbringing, parents lack of upbringing etc etc!!! Depending what a person experiences in there life gives them “facts “ to make a decision or belief

I agree but add to that the fact that people also have an imagination.
Imagination also plays a part in what people believe and its just as valid as perception and experience in that sense.

you just had to add imagination into the mix. Lol

Take a conspiracy theorist as example.
They think conspiracies exist and look for them.
When something is found that they determine to be a conspiracy, they actually believe it is a conspiracy.

Your wife and one of your co-workers are planning a surprise for you.
They talk on the phone a lot and won't tell you who they are talking to.
They are setting up meets and going places they don't want you to know about.
You think they are having an affair but they're not.
You believe they are having an affair, all evidence points to it and you have experience in the past with just that same evidence you see now, but you're wrong.
If say, you shoot them both before they can give you the surprise, you will die thinking the were having an affair. It doesn't matter what the truth was, you believe it so that is the truth.

Religions are effective because they are able to create faith in your imagination.
They can foretell events because from your point of view, those predictions come true.
No prediction ever tells exact details.
Our minds fill in the gaps to make it true.

They are able to provide moral and action guidance because people want to be lead. Its the whole reason leaders exist.
This is why you have a church service that provides a sermon.
People want to be guided, its easier than going it alone.
Just look at the world around you.
"We Don't Need No Stinkin Badges"

Point well taken... I will add imagination into it!

This. Really ANY belief, whether framed in the box of religion or not, will be affected by and solidified by these many different factors. I feel belief is only the counter to the natural instinct to wanting to know. For anything there is that we are curious about, we are hardwired, so to speak, to be prepared for BELIEF in what we find or what we are taught or experience or any combination of those things.

lol..that's why I believe what I believe....

While I agree with some of what you say, I have to balk at the idea of being 'hardwired'.
The God I believe in today is not the same God i believed in last year or in my youth. It changes as I understand my belief and I am open to new beliefs as my knowledge and wisdom grows.
Religion is what stops that expansion of belief. It doesn't want you to grow, its power resides in the "Hardwiring Baseline'.
Religion isn't flexible like life experiences are.
It expects you to change your life experiences to fit the baseline, the 'hardwiring' and anything else is an abomination of the doctrine.
I've lost count with how many times I have been told my belief in God is wrong. Its my belief?