What is true is already so.
Owning up to it doesn’t make it worse.
Not being open about it doesn’t make it go away.
And because it’s true, it is what is there to be interacted with.
Anything untrue isn’t there to be lived.
People can stand what is true,
for they are already enduring it.
—Eugene Gendlin
That's just not true, for some social environments. If you and your friends all believe X, and believing X identifies people as being members of that group, then discovering that X is false and owning up to it might make you lose a lot of friends. Depending on what you need those friends for, that might be a serious problem.
Other alternatives are:
Tell yourself the truth and lie to your friends if needed. Many people find it difficult to lie consistently for a long time; I don't think I can.
Find friends you don't need to lie to.
Take the lead and try to bring your existing friends with you as you change your mind.
There's always the default option, which is to deceive yourself.
Maybe you're lucky and X isn't really a membership-belief to start with, and these friends are already friends you don't need to lie to.
You're conflating something here. The statement only refers to "what is true", not your situation; each pronoun refers only to "what is true":