Honesty is defined as being trustworthy, sincere and credible. Let's not forget being genuine, for that's important too. Trustworthiness is defined as being dependable, reliable, and deserving of trust. I might add being consistent in there somewhere as well. It would seem to me that honesty and trustworthiness are intertwined and complement each other well.
Have you ever had an experience dealing with someone who was extremely dishonest?