For starters, from L Ron Hubbard 6 July 1958:
We have found that staff requires this prerequisite: a good Scientologist.
A long time ago they used to tell us what we needed was a good businessman. We’ve had good businessmen, and we fired them. What they used to tell us was, what we needed was a good publicity man that was really trained in publicity. And we’ve had them and they laid an egg, and we fired them.
And every once in a while we have had to fill a post with somebody who was not quite up to handling that post, and we missed. And we finally found what the common denominator was of an individual who could handle the post in an organization or any post in the organization. And that person was – the common denominator is – a good auditor. If a person is not a good auditor, there will be something wrong with his organizational activities.
Boy, that is something to remember…
…There are people around that believe that a Scientologist – a Scientologist is somebody exclusively who audits people professionally. There are a lot of Scientologists who do this. But that is not everything one does. Let me tell you that on staff, as sharp as we are about this sort of thing, we find that a person who is not a good auditor (that’s not a good Scientologist) — a good auditor, who can sit down there and turn out an excellent session, who can get good results on a preclear, is the only person we really like to have on staff because they always do a good job. They always have the ability to understand the problems of those around them, and they have the ability of handling a situation.