Certain people tend to think that by just believing or depending on their own willpower they can make mountain move. But they ignore the fact or don't know or fail to realize that belief or willpower is based on what the CREATOR  allows or disallows. No one has the power to bend things according to their own willing and against the Will of the CREATOR. .
They were allowed to have their ways in the past, it made them puffed up, and it became a stumbling block.