From IANA Ministry (I Am Not Ashamed...of the Gospel):
Today, when sin is accepted and proclaimed in public, we should be taking the Gospel to the public too. It is biblical to preach in the open air….Examples include; Noah, Jonah, Jeremiah, Nehemiah, Stephen, Paul, Phillip, George Whitefield, John and Charles Wesley, Dwight Moody, Billy Graham , oh yes..and Jesus. The United States is one of the biggest mission fields in the world. The unbelievers need to hear the proclamation of the Gospel, and they are not going to churches to hear it, and even when they do, the Gospel is rarely preached anyway.
Quotes from Charles Spurgeon on Open Air Preaching….
Certainly, Moses and Joshua found their most convenient place for addressing vast assemblies beneath the unpillared arch of heaven. Samuel closed a sermon in the field of Gilgal amid thunder and rain, by which the Lord rebuked the people and drove them to their knees. Elijah stood on Carmel, and challenged the vacillating nation with “How long halt ye between two opinions?”
Jonah, whose spirit was somewhat similar, lifted up his cry of warning in the streets of Nineveh, and in all her places of concourse gave forth the warning utterance, “Yet forty days, and Nineveh shall be overthrown!” To hear Ezra and Nehemiah “all the people gathered themselves together as one man into the street that was before the water gate.” Indeed, we find examples of open-air preaching everywhere around us in the records of the Old Testament.
We ought actually to go into the streets and lanes and highways, for there are lurkers in the hedges, tramps on the highways, street-walkers and lane-haunters, whom we shall never reach unless we pursue them into their own domains.
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