We have the stereotype that Jews are excellent!

No, we don't 'have' a stereotype unless it is our own, as viewed by others. Use the verb: We stereotype Martians as psychic.

Thanks, Mister.

Then, is it right to rewrite it as the following:

It's a stereotype that Jews are excellent.

It continues to sound odd.

Thanks, Mister.

How should I say it right?

Use what I gave you; there is nothing wrong with that.

Thanks, Mister.

Do you mean it sounds good to say "we stereotype Jews as being excellent?"

'As excellent'-- and that carries no meaning at all. And actually, I don't like your using the word 'Jews'. It is no longer acceptable.

Agreed. It is probably safer to use "Jewish people". And I'd be very, very careful about writing down stereotypes with respect to Jewish people (or any other racial group).

Thanks, Mister and Ferdis.

I hope Jewish people don't mind what I wrote in this thread.

It's an unconscious (do I use this word right?) mistake!