If you suddenly started believe in yourself you will be get some instantly changes in your self.
Believe is most powerful weapon you have in your life.
Sometimes you surrounded by bad things and you forgot believe. This is dangerous for you.
Failure and success depends on believe. If you believe you got success then you will win who knows. If you believe you will loose then you will defiantly loose.
A story of two frogs will help you in believing your self.
One time two frogs fall down in a water cane and they locked in it.
One frog loose believe and decided to not to do anything while other one try hard to get out from it. When some one open this cane second frog jump and came out from this cane but another one was died.
You can do anything if you have believe in yourself.