There are some customs for which nothing can be pleaded, except that they are very old. In such cases antiquity is of no more value than the rust upon a counterfeit coin. It is, however, a happy circumstance when the usage of ages can be pleaded for a really good and Scriptural practice, for it invests it with a halo of reverence. Now, it can be argued, with small fear of refutation, that open-air preaching is as old as preaching itself. We are at full liberty to believe that Enoch, the seventh from Adam, when he prophesied, asked for no better pulpit than the hillside, and that Noah, as a preacher of righteousness, was willing to reason with his contemporaries in the shipyard wherein his marvelous ark was built.

Instances of Open-air in the Bible

• A prophet/Moses with his brother Aaron were sent by God to pharaoh, the king of Egypt, to simply ask him, before his court, to let God's people go. Moses and Aaron did not preach the Law of God to pharaoh, nor to his court or any other Egyptian, because God knew that they were not interested in Him and therefore He did not tell His prophets to share any message of Salvation with them. They simply told pharaoh that God wanted the Israelites to leave and explained him the harsh consequences of His sin if he was not going to allow them to leave Egypt. This was the purpose and the extent of their public preaching to pharaoh before his court. They did so for Israel, not for pharaoh or for Egypt.
• In the New Testament the first example of open-air preaching we see is John the Baptist preaching publically. God had sent him to preach repentance to the nation of Israel and to prepare the "Way of the Lord", as Jesus was about to reveal Himself as the promised Messiah. Once again, just like in the Old Testament, he preached in Israel and only in Israel to God's people, to a nation who knew God and His Law. He did not preached on the corner of a street, yelling at every single person walking by, and he didn't preach how much God loved everybody, either. People gathered around him at the Jordan, because they heard he was preaching repentance, and he baptized everyone who came to him willing to renounce their sins.
• The second example of open-air preaching we see is Jesus preaching publically. He did so many times, but once again, He did so in Israel and only in Israel to His people, to a nation who knew God and had collectively followed God throughout their history, but who had been left with no shepherd to teach them the Truth in those days. For instance, we can cite the Sermon on the Mount or other episodes where he spoke to a multitude of people, but if we read carefully, it is usually them gathering around Him after hearing about Him; in Scripture we never see Him standing on a street corner yelling and calling the multitudes to gather around Him and repent. He never did anything sensational to draw attention to Himself; on the contrary, He often told people not to talk about Him.
• Then we see Jesus sending out the disciples to preach the Good News and minister to the "lost sheep of Israel". He specifically commands the disciples not to enter any city or town of the Gentiles, but to go only to the people of Israel. He also commands them saying that if the people do not receive them nor listen to their words, when they depart from that house or city, they should shake off the dust from their feet as a sign of God's rejection. Again, we see open-air preaching where the disciples go from town to town and from city to city preaching publically to people of the house of Israel who knew God and had a Covenant with Him, some of which were believers who would have received the Message and some were not. Since they had been following Jesus and had learned everything they knew from His words and His living example, it is fair to say that in those cities and town they preached the same way they saw Jesus preach, with wisdom and caution, never yelling or drawing attention.
• The next thing we find is Peter preaching publically at Pentecost, after receiving the Holy Spirit. He preaches to Jewish believers from different nations who had come back to Israel for the Holy Feasts, as it was commanded by God in the Law of the Old Testament. Once again, all this open-air preaching takes place in Israel and Peter preaches with boldness to people who had been living their entire life in the knowledge of God. The disciples of Jesus continued preaching openly in public areas in Israel to the extent that the religious authorities and the Pharisees allow them to preach openly, but when they saw persecution coming they acted accordingly: they protected themselves using wisdom, often by running away when in danger and going into hiding, if necessary.

Qualifications for an Open-air Preacher

• A good voice
• Naturalness of manner
• Self-possession
• A good knowledge of Scripture and of common things
• Ability to adapt himself to any congregation
• Good illustrative powers
• Zeal, prudence, and common sense
• A large, loving heart
• Sincere belief in all he says
• Entire dependence on the Holy Spirit for success
• A close walk with God by prayer
• A consistent walk before men by a holy life