A belief system is something we either create for ourselves, in our current lifetime a past, or something we have taken on ancestrally, most commonly from our parents, and we can accumulate thousands of them. Some may not affect our daily living but there are some that will interfere greatly with our relationships and our higher purpose.

A belief system can be created from an array of different experiences, some that you may not even remember. It could be from trauma or from something as innocent as a passing comment that has stuck in your Soul's memory, these create a program. Once these programs have been created they will be the driving force behind the way you behave, the way you deal with your triggers and conflict, the way you perceive yourself, others and situations and you will attract things, people and situations that are on the same level as that belief system until it has been cancelled and replaced on all levels. 

Some common belief systems could be, 

'I am not good enough', 'I do not deserve love,' 'I am not worthy of success,' 'I am my Mother/Father/child etc',  'My lessons come from trauma', or things more complex that have been carried through lifetimes or transgenerationally.  

The thing with programs and belief systems is that you also have the ability to pass these down to your children and so forth and these can be stored in more levels than just on a core level and thus need to be removed accordingly  to ensure they do not disrupt your Soul's journey. As an intuitive healer, this type of energy healing is a specialty of mine.