Good vs evil. Does it truly exist? What are the grey areas? Do good people do bad things?

Yes i believe it truly exist.

The are good and evil grey areas you can use it an a good way or bad way for an example some people  drink alcohol for event or celbrate which in a good and on the other side some people abuse alcohol such as start a fight or just do stuff that  unnecessary.

I believe every good person does something bad in the long run.