Credibility: (n) the quality of being believable or worthy of trust
I suppose the most logical suggestion for gaining credibility is just refusing to lie.
Seems sensible. Here’s the problem:
You can’t get anyone to believe that you’re not lying.
And the more you insist you’re telling the truth or emotionally distraught you become, the more you look like an even worse liar.
Credibility is achieved by allowing the ideas you’ve fostered to prove themselves.
To have this happen, you must be willing to silently let time pass. That way, when it ends up that the things you spoke were accurate, faithful and honest, the human race around you can slow up long enough to respond, “Hey—you were right.”
If you don’t gloat over your veracity, they will gradually—and I say, very gradually—begin to assume that you are some strange alien who has come to Earth to expose the poison of “fibbing.”
But gaining credibility is never something that can be claimed, insisted upon, lobbied for or voted into office. When people realize that your “yes” actually means yes, and your “no” holds firm at no, then maybe—yes, maybe—they will start giving you points for credibility.