Incitatus is right in that judaism, christianity and islam all have common roots but I don't think it's true to say that years of infighting have eradicated all the differences. For example, while it's true that, on the whole, jews don't believe that jesus is the messiah, there are some who treat him as a major prophet. And jesus is certainly regarded as an important prophet within islam.
There are other similarities between judaism and islam; the dietary laws, the importance of giving to charity, circumcision and various other features. The two religions stem from the two sons of Abraham, Isaac and Ishmael whose dynasties lead to the two religions. Abraham is venerated within Islam as well (Ibrahim).
Nor is true to say that all religions are based on fear and a belief in all powerful being. Buddhism for example is not and is based on belief in self-enlightenment. And Hinduism is a polytheistic religion.
I agree that they're all based on superstition and mumbo-jumbo though.