Okay kiddo, so theos kyrios is a Greek phrase made up of two words: "theos" and "kyrios". Theos means god, and kyrios means lord or ruler.
So when people say theos kyrios, they are basically saying "god is lord" or "god is ruler". It's a way of saying that god is in charge and knows what's best for us.
It's a very important idea in many religions, because it helps people understand their place in the world and how they should behave. When people believe that god is in charge, they are more likely to be respectful, humble, and follow religious teachings.
But remember, everyone has their own beliefs and ideas about theos kyrios and what it means. So it's important to be open minded and respectful to others, even if their beliefs are different than yours.