When you open air preach (or evangelize one-on-one) be careful to not use "christianized" language.

For example don't use words like "redemption," "sanctification," and "Christology" unless you want to sound like a computer programmer sounds to a carpenter.

Last night I open-aired at downtown Kalamazoo and when I mentioned "Pharisee", an unbeliever turned to his Christian friend and asked, "What's a Pharisee?" Another believer was witnessing to a guy who doesn't know Jesus and the guy said he didn't know what a "Gentile" was.

I'm learning this the hard way so save yourself some wasted breath and make sure you use terms they can understand. Instead of "redemption" say "set free." Instead of "repent" say "turn away from your sins." Instead of "Gentile" say "someone who's not a Jew." And if you must use a word for people who didn't grow up in a building with a steeple then explain it clearly.

Like Luther said, "Speak in vulgar language." "Vulgar" in his day meant the common man's language, not crude language as we use it today. See? I just had to apply my own instruction. You get the idea...