So, a revised version of your comment would be,
"The greatest things in my life aren't things. They are people. I cherish them with all I have. Everyone has their own 'greatest thing'. Everyone has something, or someone, for which they would die."

This fixes the confused messaging, the structural issues, and redundant phrasing.

Example: "We cherish them with all we have and that makes us care about it so much that it is really precious to you." Repetitive and badly structures. Poor grammar. When you write "We cherish them", you have to follow up with a pluralised subject as well (If you don't know what I mean, please look it up." So, "We cherish THEM with all we have and that makes us care about THEM..." rather than "care about it." You can't go from "Them" to "it." One is plural, one is singular, you see? You can't mix that.
Also, once you establish that someone cherishes something, there is no need to call that something precious within the same sentence, or even paragraph. Those things mean the same thing.
Lastly, you have confused your own message. Your first sentence states the important things in life aren't things, but people. Then you say people love things more than people, sometimes...

Hey not to be mean but I think you should really brush up on your understanding of English. I don't know what you mean by "my strange choice of adjectives" because there really aren't many adjectives in this quote, and none of them are out of place. This leads me to wonder whether you know what adjectives are. The grammar needs work, I won't lie to you on that front. Again, really not trying to be mean. And I see some people were mean about it. But please don't let that discourage you from learning how to speak properly. Everyone needs work in one area or another. I am ATROCIOUS with math. I'm lucky in that my issues with math aren't obvious, whereas everyone notices poor grammar, if it's bad enough. No shame, love.

This site should have server-side grammarly.

This quote is terrible. Full of errors. You didn't capitalize the start of the second sentence. Also, "and that makes us care about is so much" doesn't make sense at all. Also, "for everyone, there is their own greatest thing" is super sloppy and awkward. And you've neglected to capitalize yet another sentence - this time you have forgotten to capitalize the word "whether". You've also typed "a item" instead of "an item". And the last sentence is sloppy and awkward as well.

Take the time to edit your quotes prior to submitting them or don't post quotes in the first place please. People shouldn't have to suffer through typing your many errors!