Many years ago I learned about the Law of Belief from Brian Tracy which states that, "Whatever you believe, with emotion, becomes your reality."
The Law of Belief says that you do not necessarily believe what you see, but you see what you have already decided to believe.
Your beliefs control your realities.
You always act in a manner consistent with your inner most beliefs and convictions.
In fact, you can tell what you, or anyone else believes by simply looking at what they do.
It is not what a person says, or hopes, or writes, or wishes, or intends that is a clear indication of his beliefs.
It is only his actions.
It is only what a person actually does that tells you what he truly believes.
The great thing is that this Law of Belief is reversible as well.
Since you act in a manner consistent with your beliefs, and you can control your actions, if you engage in the actions consistent with the beliefs that you want to have about yourself and your life, you eventually develop those beliefs, just as you develop muscles by lifting weights.
For example, if you absolutely believe that you are destined to be a great success in your chosen field, and you walk, talk, act and behave every single day exactly the way a great success would act, you will eventually develop the mindset of a high performer in that field.