Evangelical: "You know what really convinces me that the Bible is true? Its coherency. So many books, so many stories, and there's no contradictions anywhere."
Me, reaching for a copy of the Bible: "OK, what about this one between ***flickflickflick*** Matthew 2:14 and ***flickflick*** Luke 2:22. One states that the family ran straight off to Egypt and stayed there until Herod had copped it. The other states that, immediately after the "time of purification" (40 days, as per Leviticus), the family went to Jerusalem. FYI, Jerusalem and Egypt are on opposite sides of Bethlehem. How is this not a contradiction?
Evangelist: "Huh, I never noticed that. Did you get that off one of your atheist websites?"
Me: "No, I got it about five minutes into a personal attempt to see how the various Gospel stories line up. It's not exactly a subtle error."
Evangelist: "Mind if I get back to you on this?"
Moral of the story: It's very easy to be sure you're right about something, simply because you haven't solicited enough critical scrutiny. I have no grounds to be smug here - I know I've done the same thing in the past. All I can say is that I'm aware of the problem and do my best to counter it.