The Christian impact on Islam was profound, and can be traced at the deepest roots of that faith. Mosques look as they do because their appearance derives from that of Eastern Christian churches in the early days of Islam. Likewise, most of the religious practices of the believers within those mosques stem from the example of Eastern Christians, including the prostrations that appear so alien to modern Westerners. The severe self-denial of Ramadan was originally based on the Eastern practice of Lent.
