Christianity is a monotheistic religion based on the life and teachings of Jesus of Nazareth (c. 6–4 BCE–c. 30 CE) as transmitted through the Bible, which comprises the Old Testament and New Testament. The Old Testament was written in Hebrew and the New Testament in Koine Greek. The whole of the Jewish Torah is included in the Old Testament along with books from the Jewish Tanak, slightly reordered. Christianity is the world’s largest religion, with about 2.5 billion followers. Christianity originated in the Middle East and slowly separated from Judaism after the Fall of Jerusalem to Rome in 70 BCE. In common with Judaism and Islam, Christianity recognises Abraham as its first prophet, hence all three are known as Abrahamic religions. About 70% of people in the West identify as Christian. The number of adherents is declining in the West but growing in Africa and Asia. In contrast to Judaism and Islam, Christian scripture holds Jesus to be the Son of God. Generally, there are no diet restrictions, but during Lent (the 40-day period of penitential preparation for Easter) some Christians fast or abstain from eating meat or other foods, especially on Fridays and Ash Wednesday. The New Testament instructs abstention from food sacrificed to idols or meat from strangled animals. Wine is incorporated in some religious ceremonies and the moderate consumption of alcoholic drinks is permitted. The Christian Sabbath (day of religious observance and abstinence from work) falls on Sundays. For observant Christians, the following holy days also require abstinence from work: Easter and Christmas Day (25 December). The dates for Easter vary from year to year and usually fall later for Orthodox Christians.