Religious traditions are subject to the dynamics of history. They come into being, they change, they suffer schisms, and they can very well become extinct.
The beginnings of these traditions occur in at least two ways. One way is for a collection of small, tribal religions to join for a common interest—for example, military protection. Apparently a group of tribes came together in ancient Israel as an amphictyony (a good word to add to your vocabulary). After suffering a series of attacks from neighboring empires, these tribes became what is now known, by Jews and Gentiles alike, as Judaism. The second way is for a founder, a charismatic leader, to establish a new tradition, either accidentally (as in the likely case of Jesus) or on purpose (as in the case of Muhammed).
Once in play, a religious tradition becomes subject to further change. Traditions expand; they move from one area to another; and within any area, they adapt to the culture of their new hosts. This is especially the case with missionary traditions such as Buddhism, Christianity, and Islam. But after the destruction of the Second Temple in 70 C.E., Judaism was forced to disperse to other regions of the world.
As for schisms, every religious tradition suffers them. These are brought about in various ways, including power struggles among the elites and the appearance of secondary charismatic figures, or secondary founders. After the death of Muhammed, there was a struggle within Islam over the question of his successor, creating the schism between Shia and Sunni. Christianity has undergone two major schisms, one between Eastern Orthodoxy and Roman Catholicism (on the question of leadership), the other between Roman Catholicism and Protestantism (brought about largely by the secondary founder Martin Luther’s breakaway from Rome).
Religious traditions die. No longer is there Egyptian religion, and ancient Greek religions have gone the way of the dodo. They have been supplanted by Islam and Christianity. And there is no reason to believe that the so-called “world religions” will exist into perpetuity, centuries or millennia from now.