if we talk about afro-asian region which dated back to AD 570 i.e,before the birth of muhammad , we can say that the religion which the local inhabitants followed was not clearly defined .Some of them worshiped stones or followed idolatry ,some of them worshiped gods and goddess mentioned in early scriptures or in folklore.Allah or AL-LILLAH was one of them .when Muhammad came into scene, he changed the notion of people and they became monotheists and in this way Islamic way of life evolved.

Islamic sources (Qur'an, hadith collections, and books of history) mention a polytheistic tribal religion. Some of the deities were Laat, Manat, Uzza, Wadd, etc. Each tribe/city may have a primary deity and temple. There were idols to these deities, vows were sworn on them, and they ware the focus of ritual worship, sacrifices etc. People may also have statues of these deities at home.

The social organization was tribal and tribal chiefs were to protect members of their tribe or individuals who had sought their protection as subordinate allied members of their tribe. Fairs held to the chief deities of the temples were also occasions for trade, poetry, and merry-making. Feeding and entertaining visitors would increase the prestige of a tribal chief and his tribe.

The social mores varied across tribes and regions. Members of a tribe were expected to participate in tribal wars, and to avenge feuds on behalf of their clan and tribe. Different kinds of marriages were prevalent, and polygamy was practiced. There doesn't seem to be a strong link between fealty to the deities and social laws.

The religious history of Arabia is rather complex.

Ismail, the oldest son of Ibrahim/Abraham, was influenced by his Father's monotheism. It is widely believed that the Kaaba in Mecca was either built or commissioned by both Ismail and Ibrahim/Abraham. What some may not know is that the Kaaba, was, in a way, the very first Monotheistic House of worship in World History dating back nearly 4000 years-(well before the Temple of Solomon in Jerusalem, centuries before the earliest Zoroastrian Temples in Persia and Uzbekistan, as well as nearly 2000 years before the earliest Churches in the Middle East and Southern Europe).

Ismail's monotheism was concurrent with the monotheism of his younger half brother, Isaac; though Isaac's son Jacob, as well as his grandson, Joseph, continued, refined and advanced the monotheistic traditions of Abraham. The direct Prophetic descendants of Isaac would establish a long monotheistic tradition thereby creating the consecutively longest-(but not the earliest) Monotheistic religion in World History......Judaism. The story of Ismail's monotheistic legacy, however, was-(comparatively and historically speaking)..... ephemeral.

After Ismail's passing, the vast majority of Arabian tribes gradually drifted away from the monotheism of Ismail and Ibrahim/Abraham and adopted a polytheistic religious system with hundreds of deities.......the Moon Deity, as one of its main Deities-(One will notice that the Crescent moon is an important symbol in Islam, though it is actually rooted in Ancient Arab paganism). For the next 2500 years-(From Post-Ismail Arabia, until Muhammad's age), Arabia was primarily-(though not exclusively), a polytheistic society.

It is incorrect to say that Arabia, during its long polytheistic period, was a major trade center. As a matter of fact, the majority of the world's ancient empires, such as, Nubia, Egypt, Babylon, Minoan Crete, Persia, Greece-(under Alexander The Great), Carthage/Greater Phoenicia, and Rome, deliberately avoided conquering or spent little time within the Arabian peninsula-(except in the very North of Arabia near Jordan-(or Ancient Nabatea). The Byzantine Empire did colonize parts of Arabia and conducted trade missions with the Arabs during the Early Middle Ages, though most ancient empires kept their distance from much of Arabia. The long, Pre-Islamic or polytheistic period within Arabia was called, "The Jahilyya"-(I know I misspelled it, my apologies).

During the Jahilyya, monotheism did appear in different parts of the Arabian peninsula. The aforementioned Byzantines had brought Christianity to this region, there was a centuries old Jewish community in the Arabian peninsula, there were probably existing-(though limited) contacts with the Persian Zoroastrian Sassanian Empire and there was the indigenous Ancient Arab Hanif tribe. The Hanifs, were one of the very few Arabian tribes who were steadfastly and uncompromisingly monotheistic during The Jahilyya. Muhammad was well aware of the Hanifs and may have been greatly influenced by them during his later years.

So even though the Ancient and early Medieval Arabian peninsula was predominantly polytheistic, the long memory of Ismail and Abraham/Ibrahim, never entirely disappeared from the Arabian peninsula during The Jahilyya years. The direct presence and even peripheral contacts with older monotheistic communities throughout the Arabian peninsula before the birth of Islam, helped influence the monotheistic orientation of many Arab communities during the later stages of the Jahilyya period. In other words, Pre-Islamic Arabia, was a polytheistic land which literally sat at the geographical and cultural crossroads of older monotheistic cultures and civilizations; though many, many centuries earlier, had built the first monotheistic temple in the history of world nearly 4000 years ago.

Short answer

Pre-Islamic Arabians were polytheistic, worshiping 360 gods; the chief god was the moon-god. They later became monotheistic because of Muhammad.

Long answer

In 1944, Gertrude Caton-Thompson (1888-1885), an influential English archaeologist, discovered a temple of the moon-god in southern Arabia. The symbols of the crescent moon and no less than 21 inscriptions with the name "sîn" were found in this temple. The temple reveals that it was active even in the Christian era. Evidence gathered from both North and South Arabia demonstrate that moon-god worship was clearly active even in Muhammad's day. ^{(from her book The Tombs and Moon Temple of Hureidah)}

The title of this moon-god, sîn, was "al-ilah" which means "the deity" or "the god", meaning he was the chief god among the Arabians' 360 other gods. Its title was commonly used as a name instead of it's actual name.

"The god il or ilah [al-ilah] was originally a phase of the moon-god" — Carleton S. Coon, (Southern Arabia, p.399).

This god's name was eventually shortened to "allah" in Pre-Islamic times. People back then even used "allah" in naming their children. For example, Muhammad's father's name was Abdullah, meaning "slave of the allah", (they say his uncle's name Abu-Talib has contains the word "allah", but I can't figure it out).

The fact that the word "allah" is never defined in the quran, and that Muhammad assumed that the Arabs already knew who allah was; proves that the pre-Islamic Arabs already worshiped allah. While they believed that allah was the greatest god, Muhammad wanted to go a step further to say that allah was the only god.

For the Arabs, Muhammad said that he still believed in their moon-god allah, but to the Jews and Christians, he said that allah was their god. But, as you can see, allah, al-ilah, sîn, "the moon-god", or whatever you want to call it, is not the God of Abraham, Isaac, and Jacob... יהוה (YHWH or Yahweh)

^{(more information here)}

I take your question as "just before the advent of Muhammad." Therefore I will not delve into ancient history, and limit the answer to late-antiquity and early Middle Ages.

First of all we have to note that people in the Arabic Peninsula could (and can) be divided geographically between the (mostly) arid North (notwithstanding oases and narrow coastal regions) and the prosperous South, with its Sabaean-Yemenite people.

The South was dominated by sedentary kingdoms, and was the Arabia Felix of Roman sources, thanks to prosperous trade and local production of spices. This land became object of a struggle between Jewish and Christan preachers, with alternate phases. Judaism penetrated in the Arabian Peninsula as earlier, and became a crucial region after the destruction of the Temple in Jerusalem in AD 70. Christianity arrived later, but its universalism demanded conversion of the local people. The apex of Judaism was reached with the conversion of the King Dhu Nuwas and the subsequent massacre of Christians of Najraan. Immediately afterwards, with the approval of Byzantium, an expedition of Ethiopians, who were Christians, conquered the Kingdom and brought its independence to an end. Judaism however survived until the advent of Islam.

The other areas of Arabia were instead populated by a complex marriage of sedentary people and nomadic Bedouins. The latter did not leave written records, but we know that the Arabic Hijaz was divided by the Christian zone of influence to the North (centred around Najraan) and the Jewish one to the South (gravitating Yathrib). These areas met in Mecca, which was to become the most important centre in the region, following the fall of the Sabaean South to the Ethiopians and the stalemate in the North between the Sasanid and Byzantine Empires.

The religion in Mecca was complex. Reportedly, at the time of the Quraysh domination, besides Christianity and Judaism a triad of goddesses was venerated: al-Laat, al-Uzzaa and Manaat. These were daughter of Allaah, which was interpreted as either the God of the Bible or another Semitic deity. In these days, Arabia became haeresium ferax, a cradle of heresy.

The importance of Judaism/Christianity was evident in that the people of Mecca, and Arabs in general, considered themselves descendents of Abraham and Ismail, which are Biblical characters.

In the Sacred Months, the Arabs from far and wide would flock to the Holy City of Mecca and its Haram, the sacred precinct, and the Kaaba. They would gather for the Ukaaz, a fair which was also a scene of poetic contests, and climb the Holy Mountain of Arafaat for the pilgrimage. In the sixth century, a new concept of Arabia Sacra was emerging, alongside with the rise of the Arabs, finally aware of being a nation.

Muhammad was born in AD 570 circa.

_{Source: A Cambridge History of Islam, and references therein.}