I love this quote from On Becoming a Person by Carl Rogers, circa 1961:
Can I be in some way which will be perceived by the other person as trustworthy, as dependable or consistent in some deep sense? Both research and experience indicate that this is very important, and over the years I have found what I believe are deeper and better ways of answering this question. I use to feel that if I fulfilled all the outer conditions of trustworthiness — keeping appointments, respecting the confidential nature of the interviews, etc. — and if I acted consistently the same during the interviews, then this condition would be fulfilled. But experience drove home the fact that to act consistently acceptant, for example, if in fact I was feeling annoyed or skeptical or some other non-acceptant feeling, was certain in the long run to be perceived as inconsistent or untrustworthy. I have come to recognize that being trustworthy does not demand that I be rigidly consistent but that I be dependably real.