grammar - Writing a novel past tense confusion

I was taught to pick a tense when writing a story. So normally I choose past tense. But how to deal with this ambiguity?

• John was brave the day before.


• John was a kind person.

Does this mean John is no longer kind?

In the story time line John is still brave as of now. But since the story happened in the past I have to use "was". How can I convey presentness within the past?

English is not my first language. I hope this make some sort of sense!