“Hockey stick” data collated in Al Gore’s film ‘An Inconvenient Truth’ is now widely accepted as gospel truth.

Gospel normally refers to the first four books of the New Testament, which are Matthew, Mark, Luke and John.  These four books are a detailed account of Jesus’ life and his teachings which are held to be absolutely true and right.  So gospel truth means absolute truth, e.g., I’m not lying to you.  What I’m saying is gospel truth.

Also the word gospel literally stands for ‘good news’.  What good news means here is the message taught by Jesus and his followers, as is written in Luke 2:11, “I bring you good news of great joy that will be for all the people.”  So if a scientist discovered the cure for cancer, we would say this was the gospel to cancer patients.