First

The less knowledge and understanding of the universe a human has, the more s/he needs to invent a quick and simple answer. God is a typical quick and simple answer.

Second

There is a difference between asking about the source that created all that we see and sense around us, and a GOD, by the common religious definition. One who is much similar to humans, but unlimited. Also because we (humans) hate our limitations, we invented a God who has none. Of course, religion that gives an image like this about God also includes so many descriptions that are incohesive. But that’s another subject.

Third

Consider yourself as part of a whole. Your purpose is to serve the whole. You have a mission during your life. You have a role. Any destruction anywhere causes some harm to the whole. The more destruction there is, the more harm there is to the whole. The more the whole is damaged, the more you (as part of it) are hurt. Therefore, it is to your benefit to seek to avoid damage as much as you can.

Fourth

What we call “death” is a term we invented. For the universe there is continuous change in composition and there is recycling. So don’t give yourself more value than you have, but also don’t underestimate your role and value.

Fifth

The purpose of your life is something you define yourself. What can I do to make things better during my temporary mission? You can be eternal through what you achieve to humanity. Beethoven, Socrates, Einstein, Thomas Edison, and million others are examples of being eternal even after their physical end which we conventionally call “death”.

Finally, I suggest you visit the web page I have created annexed to my personal web site.
It is meant to be a starting point to seek authentical and trust-worthy information in different fields and branches of science. It is in continuous development. I hope that helps. Thank you for your interest.
Central Point