Here is a great sermon from John MacArthur I got from Apologetics 315. I like the way he gives 5 things that characterizes the unbelief of people in plain contrast to facts. Her uses the unbelief of the Jewish leaders when they questioned the man Jesus healed who had been born blind.. Worth listening to.
Apologetics 315: 5 Characteristics of Willful Unbelief MP3 Audio by John MacArthur