IMO, never going to happen, at least not 100%. If I believe in something that is not true, and my belief in that belief is true and sincere, am I lying?
I should have used only sincere then. It's been shown that people can convince themselves that something they initially knew was false is true just by repeatedly lying to themselves.
If you say something that you sincerely believe is true, but isn't, then you aren't lying...you're wrong. Important difference.