Earth is clearly one of the main resources for humanity. The earth is what feeds us. It is absolutely important and we must protect it. In my country, a lot of land is used to grow crops, so Belarus is called an agrarian country, and it is associated with potatoes. Potatoes are our national property :) Therefore, our cuisine is rich in potato dishes and I'll be honest - it's very tasty. Therefore @velimir please visit Belarus and taste our local dishes :)

"Buy land because there will never be more of it," a wise man said. "...and keep it clean," I'd add. Maybe you can think of another example of something with a definite and limited supply? :D

I think the most important resource is time. Time can not be returned and we must use it as efficiently as possible. It's sad to see how many people "kill" their time doing something they do not like.
Therefore, it is worth to appreciate the time, and to spend it comfortably.
Goodnight:)