You have been desiring and longing to open air preach for years- but have yet to “break the sound barrier”. Here’s some ideas for your encouragement.
Find a friend or two you can work with; someone who can pray for you and encourage you.
Spend time in prayer beforehand. It is not you, it is the Holy Spirit in you, Who is the witness.
Consider how Jesus witnessed: He helped proud, self-righteous people see their need for a savior, by helping them see that they had sinned before a holy and just God. To humble people who were already convicted of their sin, He revealed Himself as the source of grace, mercy, forgiveness and reconciliation to God. In other words, He gave the Law of God, which reveals our sinfulness, to the proud, and He gave Grace (the message of the cross and God’s gift of salvation through faith in Jesus) to the humble. You can use this “Law and Grace” idea as your basic outline, as you prepare your gospel message.
Write down your message as an outline, or even write it all out completely. You can read it word for word from the paper. Can’t think of a message to write? You can read a tract aloud, or read a passage from the Bible.
Humble yourself, because it does not matter how old you are, what you sound like, or how well you can speak. Trust God; He wants to use you to bring His message to those who need to hear.
Here is a wonderful story from The Lawman Chronicles, of one person’s first time open air. Tony Miano writes:
The important thing is not how polished the preacher looks or sounds. The power of the message is in the message itself; and the most important thing the preacher brings to the message is faith and obedience–not humor, an extensive vocabulary, or eloquence.