She's always spreading/preaching the 'gospel' of good health. [=telling people about the importance of good health]
I didn't do it, and that's 'the gospel truth'. [=the absolute truth; a completely true statement]
These myths are 'accepted/taken as gospel' [=believed to be true] by many teenagers.
(..) think that has something to do with this? We need these men well-rested to bring in this well. They can't get that if they're up here listening to your gospel, and then the well can't produce and blow gold all over the place. I wish I had more time with Joe Gundha. More could have been done. (..)2007 There Will Be Blood