You should have a spirit that's humble when before a god. You never really have to act all nice and humble before anyone else, but if you meet a god... well... you should probably lower yourself appropriately. They can smite you and all that.
When you see a god, you need to get down on your shins (しん). Get down on your ankles? No, not low enough. Knees? No, no, get your shins flat on the ground to show how humble you really are.