Disregarding someone's irrational beliefs (every one of us has some) just like that is a sign of serious lack of empathy, and an easy way to make enemies. You can try and convince someone to stop holding that irrational belief, but you don't have to disrespect their feelings in the process.

Without irrational beliefs there is no meaning to life.

I don't see how that is even a remotely justifiable belief.

So give me a rational meaning to life :)

One man's irrational beliefs are another man's rational.

Yeah, that's how it works. /s