Throughout history, Christians have used many different approaches to spread Christianity via the practice of evangelism. Christianity began with only a few different evangelistic approaches, but over the years, many different forms of evangelism have been employed by various groups to spread their faith. Many of these forms of evangelism are often employed in only certain parts of the world by Christians in different geographical areas. In particular, most new approaches to evangelism today have arisen out of Europe or the United States, especially when new technologies are used for the effort of evangelism..
Open-air preaching is an approach to evangelism characterized by speaking in public places out in the open, generally to crowds of people at a time, using a message, sermon, or speech which spreads the gospel. Supporters of this approach note that both Jesus and many of the Old Testament prophets often preached about God in public places. It is one of the oldest approaches to evangelism.
One of the earliest open-air preachers of Christianity, according to the gospels, was Jesus Christ, whose first specifically recorded sermon was the Sermon on the Mount, which took place on a mountainside in the open air. In the Gospel of Luke (Luke 6:17-49), it was recorded that Jesus also gave an open-air sermon known as the Sermon on the Plain.
After Jesus' death, many of his apostles and followers open-air preached the gospel in the Temple of Jerusalem or in other open spaces.
During the Middle Ages it was used. During Protestant Reformation, open-air preaching was often employed by Protestants throughout Europe who could not always preach inside churches, which were mostly Catholic. Open-air preaching in Europe continued during the rise of Puritanism and other Protestant movements. It was often used in Pastoral environments as well as in cities, the former sometimes due to a desire to avoid the authorities, and the latter because, for one reason, it could reach eccentric people living in cities who would not otherwise hear the gospel.