One who conceals his sins will not succeed (Proverbs 28:13).
Another verse states, Fortunate is one who conceals his faults (Psalms 32:1). How are these two verses to be reconciled?
There are two types of concealment. People who realize that they have done wrong and now feel bad about it are obviously not likely to make a public declaration. Rather, they will be remorseful and resolve not to make the same mistake again. They do not deceive themselves and think they have done no wrong. The Psalmist speaks of these people and says, Fortunate is he whose sins God will not consider, and there is no deceit in his spirit (ibid. 32:2). This honesty leads to forgiveness, and the concealment referred to is in contrast to those who flaunt their wrongful behavior, thereby indicating that they believe it to be correct.
Proverbs is referring to those who conceal their sins from themselves, either by repression or by any of the many distortions that people use to justify their errant behavior. These people are dishonest with themselves, and they stand in contrast to the person who "has no deceit in his spirit."
Obviously, people who deceive themselves cannot be honest with others, even if they try to do so. The unlucky prospector, for instance, who actually believes that his fool's gold is genuine, will think he is being honest when he sells it as genuine. If his "innocent" dishonesty is exposed, his loss of trustworthiness will preclude his being successful in anything else.
Honesty is certainly commendable, but we must first make certain that we are honest with ourselves.