refer to religion as a largely invariant phenomenon that should be distinguished from cultural norms (i.e. religions). Morphological classification Some scholars classify religions as either universal religions that seek worldwide acceptance and actively look for new converts, such as Christianity, Islam, Buddhism and Jainism, while ethnic religions are identified with a particular ethnic group and do not seek converts. Others reject the distinction, pointing out that all religious practices, whatever their philosophical origin, are ethnic because they come from a particular culture. Demographic classification The five largest religious groups by world population, estimated to account for 5.8 billion people and 84% of the population, are Christianity, Islam, Buddhism, Hinduism (with the relative numbers for Buddhism and Hinduism dependent on the extent of syncretism) and traditional folk religion. A global poll in 2012 surveyed 57 countries and reported that 59% of the world's population identified as religious, 23% as not religious, 13% as convinced atheists, and also a 9% decrease in identification as religious when compared to the 2005 average from 39 countries. A follow-up poll in 2015 found that 63% of the globe identified as religious, 22% as not religious, and 11% as convinced atheists. On average, women are more religious than men. Some people follow multiple religions or multiple religious principles at the same time, regardless of whether or not the religious principles they follow traditionally allow for syncretism. A 2017 Pew projection suggests that Islam will overtake Christianity as the plurality religion by 2075. Unaffiliated populations are projected to drop, even when taking disaffiliation rates into account, due to differences in birth rates. Scholars have indicated that global religiosity may be increasing due to religious countries having higher birth rates in general. Specific religions Abrahamic Abrahamic religions are monotheistic religions which believe they descend from Abraham. Judaism Judaism is the oldest Abrahamic religion, originating in the people of ancient Israel and Judah. The Torah is its foundational text, and is part of the larger text known as the Tanakh or Hebrew Bible. It is supplemented by oral tradition, set down in written form in later texts such as the Midrash and the Talmud. Judaism includes a wide corpus of texts, practices, theological positions, and forms of organization. Within Judaism there are a variety of movements, most of which emerged from Rabbinic Judaism, which holds that God revealed his laws and commandments to Moses on Mount Sinai in the