ELI5: Explain Like I'm 5

Arianism

Okay kiddo, so Arianism is a way of thinking about God that was popular a long, long time ago.

Some people who believed in Arianism thought that God the Father was more important than Jesus, his son. They thought that Jesus was created by God and was kind of like a superhero or a really powerful angel, but not fully God.

Other people, who believed in the more traditional idea of Christianity, thought that Jesus and God the Father were both fully God and equal.

This caused a lot of arguments and disagreements among people who followed Christianity back then. In fact, the argument got so big that a big meeting was held called the Council of Nicaea, where they tried to figure out who was right.

In the end, they decided that Jesus and God the Father were both fully God and equal, and that Arianism was not the right way to think about God.

Nowadays, most people who follow Christianity believe in the traditional idea that Jesus and God the Father are both fully God and equal.