Judaism is strictly monotheistic, while Zoroastrianism is somewhat dualist (with a strong anti-God). However, Zoroastrianism has a streak of messianism in it along with belief in an afterlife with heaven and hell. These are comparable to the messianism of second-Temple Judaism, and and some speculate that these elements were picked up by the Jewish community during the Babylonian exile. Interaction between Jews and Zoroastrians may have begun then, but it continued through the redaction of the Babylonian Talmud, which records a number of interactions between Zoroastrians and Jews -- many of which suggest long discussions may have taken place without ever coming to any kind of theological agreement.
There are numerous amounts of religions and spiritual beliefs in early Europe. Some of the known religions are: Wicca, Druid, various forms of Paganism, and Judaism.
Islam is an Abrahamic religion, and thus has its roots in Judaism and is connected to Christianity, as they all worship the same god. Islam originated with the prophet Muhammad, who Muslims believe to be a prophet of the god of Abraham.
the belief in One God.
Early Judaism believed in one G-d (in a form of either monotheism or henotheism).Early Judaism rejected the idea of praying to a physical image of a deity.
Islam, early 7th century a.d.
Early religious beliefs served as ways to explain the unnatural events that sometimes occued in the ancient world (storms, earthquakes, floods, etc...). These beliefs grew into someone/soemthing/somethings controlling these events, which in turn lead to established early religions such as Zoroastrianism, Judaism, Christinaity, Islam, Hinduism, Buddhism, Shinto, Animism, and many other religions that still exist today.
The early Roman Empire persecuted followers of both religions but ultimately did not stem the growth of either religion. - APEX
Answer 1They were treated with tolerance. Islam believes in peaceful co-existace with all humans belonging to any religion as long as they don't create trouble for the Muslims.Answer 2It depended on the size of the religion (in terms of how many adherents it had). Smaller religions, especially polytheist and henotheist Arabian religions were forcibly repressed and made to convert to Islam. Mohammed himself smashed most of their idols when he retook the Ka'aba in 630 C.E. With larger religions like Zoroastrianism and Hinduism, Muslims realized early on that they could not effectively bully these religions into non-existence, so they passed a number of repressive edicts, taxes, and lifestyle requirements in order to make Zoroastrian or Hindu life odious enough to incentivize conversion. It was reasonably, but not completely effective. It would take later repression (under the Safavids and Qajjars) to effectively extinguish Zoroastrianism. And Hinduism survived in India due to sheer numbers.Of course, you now have revisionism (such as in Answer 1) which seeks to claim that early Muslims were pleasant angels to everyone they conquered.
There is no one single characteristic that sets Christianity apart from other religions. Christianity is monotheistic, but so are Judaism, Islam, Sikhism, Zoroastrianism and other religions. Christianity shares the abrahamic God with Judaism and Islam. Christianity was largely spread by imperial edict and conquest, but the early spread of Islam has many parallels. Christianity teaches high moral principles, but so also do other religions. In Christianity, Jesus came to earth and was born of a virgin, but virgin birth was common among the ancient religions. The Zoroastrian Saoshyant, who will also be born of a virgin, has many parallels with Jesus, but has not yet come to earth. The Christian Jesus was crucified, but again, there were other gods, goddesses and demigods who were crucified. Perhaps the one thing that sets Christianity apart is that it is the dominant religion of the powerful and prosperous West. This provides for some a sense that Christianity was destined to dominate the world.
Abraham, founder of Judaism, was surrounded by various Pagan cults and religions, all of which were Polytheistic - they worshiped an array of deities. Judaism was a radical departure from this. Abraham made an eternal covenant with the Gd of Israel in which he vowed to stay true to this, the true Gd. In return, Gd would protect Abraham and all of his decedents. Judaism was the first organised faith to advocate pure Monotheism, then. This made it totally different from the religions and cults that surrounded the early Israelites.
The origins of Christianity are clearly in the early Jewish faith. Some see further influences from Greek paganism and ancient Greek philosophy, particularly Platonism. Others say that Christianity could have evolved from the mystery religions.
Immacolata Aulisa has written: 'Dialogo di Papisco e Filone' -- subject(s): Early works to 1800, Judaism, Controversial literature, Apologetics, Christianity and other religions