Okay kiddo, so you know how some people believe in Jesus and follow the teachings of the Bible? Well, sometimes people change their minds and they stop believing in Jesus or they stop following the Bible. This is called apostasy.
Some people think that apostasy is a very bad thing because they believe that by turning away from Jesus or the Bible, you are rejecting God. Other people think that changing your beliefs is okay because everyone has the right to think and feel what they want.
In Christianity, apostasy is often seen as a sin because it goes against the teachings of the Bible. The Bible tells us to believe in Jesus and follow his teachings, so when someone stops doing that, it is seen as a bad thing.
However, many Christians also believe in forgiveness and that people can change their ways. So, even if someone has committed apostasy, they can ask for forgiveness and try to start following Jesus again.
It's important to remember that everyone has the right to their own beliefs and opinions, and apostasy is just one example of how people's beliefs can change over time.