I think a very straightforward contradiction is here: http://skepticsannotatedbible.com/contra/horsemen.html

2 Samuel and 1 Chronicles are supposed to be parallels, telling the same story. Yet one of them probably lost or gained a zero along the way. Many christians that see this are foreced to retreat to a more 'soft' interpretation of the bible that allows for errors in transactiption etc. It's the closest to a quick 'n' dirty sledgehammer I have ever had. And a folow-up: Why hasn't this been discussed in your church? Surely, a group of truthseekers wouldn't shy away from such fundamental criticisms, even to diffuse them.