Prayer is one of the oldest social rituals. It was originally created as part of animism, the earliest belief system, and has extended through history as a part of organized religions.
Prayer is based on the concept of direct contact and appeal to deities. A god or gods is worshipped on a structured formal basis, with a personal element in private prayer which includes praying for loved ones and other personal concerns.
The history of prayer
The oldest extant forms of prayer are rituals in old cultures like the Australian aboriginals. These are true social rituals, with direct ceremonial and lifestyle applications which can be seen in modern religions to this day. Some are rituals related to coming of age, or initiation rites for children passing to adulthood with associated ceremonies.
Of the modern religions, the oldest is Hinduism, which is a highly structured religion involving a pantheon of deities. This pattern of prayer extends to the monotheistic religions in various forms, including praying to saints, worship at holy places, and similar practices.
Of the modern religions, the oldest is Judaism, which is related to both Islam and Christianity in terms of being the antecedent of both the other Abrahamic religions. Judaism is 5000 years old, and was the first of the modern monotheistic religions. Christianity is a direct offshoot of Judaism, and contains a common theological basis with it in the Old Testament.
Methods of prayer, however, have digressed between these two religions. The Judaist form of prayer is believed to have been the original form of prayer of the two religions. Christianity uses both prayer and hymns as forms of prayer, whereas Judaism uses a sung form of prayer expressed by a priest. Christian forms of prayer vary considerably among the different religions.
Islam is the youngest of the monotheistic religions, which makes reference to both Judaism and Christianity in its texts. Islamic methods of prayer are described in the Koran, and are formal, preset forms of worship which may be conducted privately or in a social setting in a place of worship.
Other types of prayer
The other major forms of modern prayer are Asian. In China, Confucianism has a ceremonial form of prayer, using various methods to perform religious duties. This is a somewhat different form of prayer, derived from the teachings of Confucius and Mencius, using materials to perform ceremonies at particular times, or under certain conditions. Taoism, the other major Chinese belief, is a pantheistic system derived from the Taoist philosophy. It's essentially a similar. This religion is 2500 years old, and prayer practices can be quite variable. Recitation of passages from the Tao Teh Ching are among the prayer methods.
The other major modern religions, Buddhism, has a thoroughly laid out form of prayer and religious instruction based on religious teachings and practices. Buddhism is a development of Hinduism, founded by Gautama Buddha also about 2500 years ago. Prayer is based on memorized learning, and application of prayers to spiritual circumstances. In its most advanced forms, Buddhism can be complex, but it's very well structured for teaching purposes. Zen is a method of learning which applies the teachings of Buddhism to worldly situations.
Native American religions form another important religious group. This very diverse group of religions is also highly structured, using stories to illustrate spiritual meanings. Practices include ritual, personal prayer, and initiation ceremonies. It will be noted that these beliefs use methodologies similar to all the animist and the monotheistic and polytheistic belief systems.
There's reason to believe that over time religious practices have adopted both ancient cultural processes and the practices of others, as well as creating their own methods of prayer and worship. There are many similarities in the religions, and many common practices, of which prayer is the most common.
Prayer appears to have developed as a medium of spiritual religious practice in all cultures, in some form. Although the methods of prayer may vary greatly, the practices are designed to fulfill the same purposes.