God see things as they really are. If we accept the idea that he is the happiest of all beings, and that the more like him in character and knowledge we are, the happier we will be, we too must learn to view things as they really are. This is what it means to be honest.
Dishonesty is the degree to which we think, feel, or act inconsistently to what we know. It is the degree to which we are at odds with things as they really are, as far as we understand reality.
Honesty is like a seesaw—it is easy to be off to one side or the other, but very difficult to be balanced. People tend either to be too hard on themselves (one form of dishonesty) or not hard enough on themselves (another form of dishonesty). They tend to be too exacting of others (another form of dishonesty) or too quick to make excuses for others (another form of dishonesty).
Dishonesty blocks opportunities for both increased joy and reduced suffering.