Shirk (polytheism)

Shirk is when someone believes in more than one god or has a partner for Allah. It's like when you have two best friends and you like them both the same but you can only have one best friend. Allah wants us to believe in him and only him because he is the only one who made everything in the world and controls everything. If we believe in other gods, it makes Allah sad because he wants us to be his special friends and trust only him.