The Book of Proverbs in the Old Testament is, in my opinion, one of the best business books ever published. One passage, in particular, contains a world of business wisdom: "As a man believes so is he." (23:7)

In the past, I've written in this blog about the beliefs that make people more successful. However, I've observed that there are five other beliefs that consistently make people less successful. Make sure you don't subscribe to any of these

1. My self-worth is based on what others think of me.

Some people define themselves based upon how they guess their boss, co-workers, relatives and friends see them. When they are convinced that others think poorly of them, such people lack the self-confidence necessary to consistently take action.

2. My past equals my future.

When some people experience a series of setbacks, they assume that their goals are not achievable. Over time, they become dispirited and discouraged, and avoid situations where failure is a risk. Because any significant effort entails risk, such people are then unable to make significant achievements.

3. My destiny is controlled by the supernatural.

Some people believe that their status in life–or even their potential as a human being–is determined by luck, fate, or divine intervention. This all-too-common (and ultimately silly) belief robs such people of initiative, making them passive as they wait for their "luck" to change.

4. My emotions accurately reflect objective reality.

Some people believe that their emotions are caused by external events. In truth, though emotions are determined by the perception of those events, combined with preconceptions about what those events mean. Such people find it difficult or impossible to "get out of their own heads" and see situations from another person's viewpoint.

5. My goal is to be perfect or do something perfectly.

Because perfection is unattainable, the people who seek it are simply setting themselves up for disappointment. Perfectionists blame the world (and everything in it) rather than doing what's necessary to accomplish extraordinary results. That's why "successful perfectionist" is an oxymoron.

If you're suffering from any of these five beliefs, I strongly recommend expunging them in favor of better beliefs. I explain how to do this in this post "How to Be Happy at Work" (in the post, I call them "rules", but that's the same thing as "beliefs.")