Several months ago I was tasked with writing some evangelistic material for Gospel.com. In the course of doing so I read a whole lot of "evangelism pitches" on Christian websites of every shape and size—I wanted to see how my fellow evangelicals were stating the case for Christ.

The truth was, I found an awful lot of evangelical Gospel presentations (including some that I myself had written in the past—I'm not pointing my finger at anybody) just... unconvincing. It was hard to pick out just why that was, because most of the presentations I found lacking got all the important facts (Jesus, sin, the resurrection, etc.) right. I just found it hard to imagine anybody being convinced by them.

This all came to mind when I read a recent post by Fred Clark at Slacktivist picking apart a "Gospel presentation" scene in the Left Behind novel. I don't want to debate the literary quality or theological accuracy of Left Behind here, but Fred hits on a common problem with evangelical Gospel presentations: they employ circular logic and assume that the reader—who may not believe in the Bible at all—nevertheless shares certain assumptions about the authority of the Bible. Fred criticizes a Gospel presentation style that uses the Bible itself (verses like 2 Timothy 3:16) as a proof-text for the claims of the Gospel:

The assumption here is that "chapter and verse from the Bible to back it up" provides an irrefutable, indisputable trump card. The confusion here is not unique to LaHaye and Jenkins -- it's a common notion among American evangelicals.

II Timothy 3:16 sums up what we evangelicals believe about the Bible: "All scripture is given by inspiration of God." But evangelicals rarely cite this passage as a mere statement or summary of what they believe. They cite it, rather, as though it were proof and validation of that belief. (See also II Peter 1:21, Psalm 119, etc.) Every word in the Bible is true. How do we know? Because it says so right here in the Bible and every word in the Bible is true.

I've seen many Gospel presentations that, arguing for the reliability of Jesus and his claims, cite things like the hundreds of eyewitnesses to the resurrected Jesus, the vast number of Old Testament prophecies fulfilled in the New Testament, and other instances where one Bible passage provides supporting evidence for claims made elsewhere in the Bible. These things make a powerful case for the Bible's internal consistency, and they can strengthen the faith of somebody who accepts the authority of the Bible—but to somebody who doesn't trust the Bible, they are are no good as arguments for the truth of its claims.

Have you ever run into this situation when sharing the Gospel with somebody? Has somebody ever challenged you to point to evidence for a Biblical claim, and you found that the only evidence you could point to was within the Bible itself? What do you do in this situation?

For me, this is an illustration of several difficult truths about evangelism. For one, it shows the weakness of a Gospel presentation that relies on "proofs" and ironclad logic—most of the proofs we evangelicals cite assume a belief in the Bible. And secondly, it points to the wondrous paradox of sharing the Gospel: it's we humans who are called to tell the Good News, but it's God alone who has the power to touch a hardened skeptical heart.