Why cant everyone just agree on one religion?

Because we are stubborn and rebellious.

We want God our way and on our own terms.

Your assumption that they all are the same is false. Different religions have different ways of attaining salvation, becoming right with God, or whatever you want to call it. Radical Muslims tell you that one must serve Allah by killing infidels. Most other Muslims will tell you to be a good person. Christianity says that Jesus has paid for the unrighteousness which is inherent in us from the moment of conception. The justice God had demanded has been appeased through this. These are fundamental differences between certain religions.

Because everyone is different. That's why the idea of one "true" religion makes no sense. No "loving" god would make us all so very different and unique, give us all such varying lives, experiences and perspectives, and then require that we all have exactly the same understanding about such an arbitrary things as "purpose" or "creation" or even "morality".

And all religions do NOT "all have the same basic beliefs".

Real answer

Because lets say everyone in usa accepted budhism all the priests and other million air churches etc would go broke, hence they fear losing social standing and will stick to what ever that can fork them in some cash even if they know what they are preaching is bull ****

Same goes for politicians, they lie to maintain lifestyles and a pay check other wise they would not have a job (same for lawyers now that i think about it)

No they don't have the same basic beliefs.

For example I know the word Christ is Celtic pagan for the Sun messiah. And that Christianity plagiarized the Celtic pagan culture, terminology, festivals dates and all.

Christianity believes in a giant invisible man that lives in the sky. Who fathered a son called Jesus who is coming back via or through the clouds.

Now what sounds more likely to be coming back to pay a visit through the clouds, a dead man called Jesus or the sun in a different light. :)

Christianity is fiction.

Practicing Shaman.. quantum physics rocks.

Unless your an atheist.

Or unless you look into religion deep enough to realize the complicated rituals, controversial beliefs and clashing ideals.

People believe different things, no one should have to agree on anything.

That's about as productive as asking "Why can't everyone agree on the same ice cream flavor?"

Because "religion" is basically an illogical response to fear, the product of people inventing ludicrous stories about Imaginary Sky Daddies to help them cope with their fears....it would make no sense for already non-sensical beliefs to be "rationalized"!

People can't even agree on breakfast - what makes you think they'll agree to one religion?

I think you'll find the basic beliefs are only relatively compatible for most of the Abrahamic religions. Not so for the others.

No religion

I'll have Norse, Chinese & Greek gods as one religion and give it a whole new name if I must, but then the people will fight over who's right or wrong.

wow..of course we can be agreed on one religion; if we want to.. but....well actually we can't..if we could, all our world problems would be solved. It will be so boring..no wars, no killing, no churches, no compromises, not straggling to accept each other the way we are, no rasism..nope, this is the only thing that keeps us on our toes. It makes us feel alive..and it's good for TV ratings as they run the world..it's good business all over the world. Why do you wanna spoil it..