Maintain a humble, gentle, and patient disposition
Your demeanor is very important. Even if you don’t think that you are being cocky or impatient, or overly aggressive it is important to understand how you are being perceived. Public preachers are already stereotyped as “condescending” and “ignorant”. We have to work extra hard to overcome this. Not that we should be putting too much stock in what others think of us either, that can be equally as harmful. To simply desire that “all men speak well of you” (Luke 6:26) is not to follow in the path of our Savior either. We should be sure that we are going the extra mile to effectively communicate. We can’t let our personal disposition be a stumblingblock to our message. Avoid becoming (or even looking, as much as is possible) defensive, or arrogant.
Anger is not always bad. Jesus flipped the tables over and whipped the Pharisees out of the temple, but this was not His general disposition. Paul in Acts 13 harshly rebuked a man and cursed him with blindness, but this wasn’t an everyday thing. These men were balanced. “The servant of the Lord must…be gentle to all, able to teach, patient, in humility correcting those who are in opposition…” II Timothy 2:24
Use hecklers properly, work to control the crowd
A heckler is your friend. Ray Comfort has some great material on this. I will add a few of my own thoughts. When someone engages you, use them to attract others into your discussion. Let the heckler ask questions that others probably have but don’t have the courage to publicly ask you. It’s like batting practice in baseball. You don’t have to answer every question, especially when you have five or six people asking questions at once. Wait for the question you want and take the discussion where you want. This is a vital part of controlling a crowd.
When a crowd gets to be a bit wild you can use some tactics to calm things down. I often will ignore the hecklers who are just trying to be disruptive (there can be bad hecklers). If they don’t leave then I try to shame them publicly by saying things like “Man, I am here to have an honest discussion about important things, are you not mature enough to do that or what?” This many times will get an irrational person to calm down and when done to a whole crowd can calm a whole crowd down. If they are only getting irate and argumentative then you are not going to be able to effectively communicate with them, work to calm things down, control the crowd, work for a dialogue, an exchange of ideas and thoughts (this also means that you have to be willing to listen too).
Another important thing is to not let yourself get bogged down with one person in a crowd. If you have twenty or thirty people standing in front of you listening, and one person gets real close up to you and wants to have a “personal” conversation then you will need to let them know that you are interacting with a large crowd, they can either join in, talk to someone else in your group who may be doing one-on-one stuff, or simply ask them to wait until you are done, offering them your email or something. Here you have to use discernment too. There have been times where I have preached for a while and the crowds are thinning out (or never built up in the first place) and a sincere person comes up and wants to talk, Sometimes it may be that you need to stop preaching and talk to this person. There have been times where I have preached it seems just for one person who was drawn in and I was able to really minister to them on a personal level. Don’t be afraid to stop preaching in these instances.
Be prayed up
Be in prayer as a way of life, but especially while engaged in open air preaching and witnessing. There are many times I have gone out ministering “in the flesh” and my preaching is off, my spirit is bad, and I simply need to recognize it, shut up and get my heart right with the Lord. Pride or irritability can do more harm than good.
Don’t think that simple fear is an excuse in this instance though to not preach. Work through your fear. NEVER let fear hold you back from being obedient. Every time I go out, despite fear, I get greatly blessed as a result (as do others whom I come into contact with).
Define terms, clarify points, be careful to communicate effectively
Many times we fall into using Christian “lingo” that non-Christians don’t understand. “You must be born again!” shouts a zealous young preacher. Okay, what does born again mean? Your average young person in America doesn’t know what that term means. It requires some explanation. If we are going to say it, then we need to at the same time DEFINE IT. I have found that about 90% of confusion and miscommunication in witnessing is a result of people using a word when the hearer has a different definition in their mind. Another example of this is when someone might say in regards to homosexuality, “What’s wrong with two men loving each other?” My response is, “Nothing, two men should love each other, I love lot’s of men!” Then I will clarify the definition of the term love, “Lust, or sex, is not love. “Two men should love each other, they should not have sex with each other.”
Use the Law, touch the conscience, speak to the heart
If you have never heard “Hell’s Best Kept Secret” I would encourage you to listen to it. The Law of God, written on every man’s heart, is evidence of right and wrong and is also evidence for God’s existence and authority. The Holy Spirit came into the world “to convict the world of sin, of righteousness, and of judgment to come.” John 16:8. We are not helping anyone by tickling ears and telling them what they want to hear. A sinner who thinks all his problems will go away if he becomes a Christian is not coming to Christ for the right reason and when he finds out that his problems don’t go away but may even get harder he will most likely fall away. The law is the “schoolmaster that brings us to Christ”, (Galatians 3:24). Men must come to Christ through the cross, broken over their sin and ready to submit to the rightful authority of their Creator.
This does not mean we don’t use reason and appeal to the mind as well. As Charles Finney would say, you go through the head and into the heart; you must make sense to the person for the conscience to be struck. Thus God’s Law, when presented properly, brings genuine conviction of sin. A man must see the shame of his sin before he’ll see the need for a savior and before he will appreciate what Christ did for him. The deeper the conviction of sin, the deeper the repentance; the deeper the repentance the deeper the Christian life that will be produced.