Some priest spells that aren't obvious don't need to be flashy.
Like Path of Truth
by Mister Anderson. Zone of Truth can just represent that some people find it extremely hard to lie around him, like a presence, or great lie detection ability. True seeing can just be someone who catches every
detail. As for detect lies, think of Lie to Me.
I'm sure there's plenty more examples in the actual book, but I'm away from it at the moment - just consider that spells don't need to be spells
, especially when a priest casts it without spell points or crazy hand gestures.