Can a person TRULY be happy living in a world full of uncertainties? [Spirituality & Religion]

As far as uncertainties go, that will be a constant.
So, if people want to be happy, they have to accept that.

Well...You really need both..Those are the first two of the six human needs...the first is establish certainty...things you can without a doubt rely on...once that is established you need uncertainty/variety...a long discussion for further insight...but that core of certainty is required.

Depends on what they put their hope in.

Focus on what you have, not what you do not.

Yes 😊