As expected, it commonly originated from Judaism or at least a subset of it. There have been some suspicions about the monotheistic religions originating from zoroastrianism (which is in Iran). However Abrahamic religions don’t seem as fond of dogs the way zoroastrianism is. There is even a persistent suspicion of them among Hasidic Jews, some Orthodox Christians and Muslims.
As what others suggested, zoroastrianism is influenced by Judaism to a lesser extent and even then it was displaced by Islam and Christianity. Even Bangladesh started out Buddhist and became Muslim. Christianity as it originally formed still exists among Oriental Orthodox churches in Egypt, Syria and Armenia to varying degrees. They believe that Jesus’s divine and human nature are the same.
As to why Christianity (and possibly Judaism and Islam) diverged into several branches is due to schism or growing differences in practises and theology. An early schism led to the Roman Catholic Church (which absorbed Greek teachings) and Eastern Orthodox (which didn’t). The former begat Protestantism which in turn begat several branches.
There is still ongoing persecution, especially among Copts but this is the very reason why Christianity, Islam and Judaism spread globally.