So why do I believe it? Because it makes sense to me. I would guess that it's the same for everyone else. By trying to prevent this lie from being spread you are rejecting the fact that I reached this conclusion in a valid manner because you don't agree with it.
That's an opinion, not a lie. A lie would be saying "pigs grow on trees", "in a monarchy the king is chosen in an election every four years" or "the earth is flat", to put some examples.
> So why do I believe it? Because it makes sense to me.
What is it then, people believe lies because it makes sense to them or because other people lie?
Because reality is not so clear cut as "pigs grow on trees". No one is claiming anything as ludicrous as pigs grow on trees in our political debates. Disagreeing with most of the narrative on climate change is not the same as saying pigs grow on trees, for instance.