When we understand dhamma, the anxieties disappear and everything is clear. Anxieties are due to attachments. Fear of losing something or someone we hold tight thinking they are permanent, and stay the same for ever. This is the opposite of nature – all things, ideologies are in constant flux and change.
Also, when we loosen our attachments and spread love and kindness to all, the world becomes beautiful too because you treat everything with equanimity. The child next door is no different than your own child.
There is also no real concrete “birth” and “death” events. We “become” (appear) and pass away. Where were we before we were born? We do not know.
Meditating makes our minds peaceful because it makes us understand the true nature of the world.