Final answer:
The basic pre-Islamic religion was characterized by polytheistic worship, including a supreme deity and a multitude of secondary deities, idols, and ancestral spirits.
Step-by-step explanation:
The main characteristic of the basic pre-Islamic religion is polytheistic worship. The pre-Islamic period in Arabia consisted of a variety of religious practices, among them a form of polytheism where various deities were worshipped. These included not just a collection of idols and totems but also a distant supreme deity, akin to the concept of a creator god, yet not directly involved in daily human affairs. This supreme being was worshipped alongside an array of secondary gods and ancestral spirits that were believed to influence various aspects of daily life and natural occurrences.
The pre-Islamic religious landscape was complex and multifaceted, holding in esteem a multitude of gods housed in places like the Kaaba in Mecca, which was already a major site of religious pilgrimage. In contrast to the polytheistic practices, Arabian polytheists were contemporaries with monotheistic groups, including Christians and Jews, highlighting the religious diversity of the region prior to the emergence of Islam.