Asking this question is a bit like asking "Why do we believe in God?"
And the answer is that belief in God is not universal. Also, if you really talk to people in earnest, individuals who generally agree that God exists don't agree on a lot of other things pertaining to God and will have come to their belief by different pathways.
There are things for which there is enough consensus that it is socially acceptable to talk about it publicly. That doesn't mean everyone agrees. That just means most dissenters have the good sense to keep their thoughts to themselves and those that don't get mocked, pilloried, etc.
Asking this question is a bit like asking "Why do we believe in God?"
And the answer is that belief in God is not universal. Also, if you really talk to people in earnest, individuals who generally agree that God exists don't agree on a lot of other things pertaining to God and will have come to their belief by different pathways.
There are things for which there is enough consensus that it is socially acceptable to talk about it publicly. That doesn't mean everyone agrees. That just means most dissenters have the good sense to keep their thoughts to themselves and those that don't get mocked, pilloried, etc.
See also Overton Window.
https://en.m.wikipedia.org/wiki/Overton_window