To master believing, all you have to do is tip the balance of your thoughts, words, and actions, from 'not believing' to believing. The ONLY thing that can ever get in the way of manifesting what you want, is having more thoughts of 'not believing', speaking more words of 'not believing', and taking more actions of 'not believing', than you are of believing. Base the majority of your thoughts, words, and actions in believing, and the law of attraction must obey you.
Believing contains no doubt. Believing does not waiver. Believing is absolute faith. Believing remains steadfast despite what is happening in the outside world.
Here is a story of believing that will speak to you and inspire you......... to believe.
May the joy be with you,