Sometimes a liar's mouth can be full of truth
I done heard gospel from a sinner
from Joe Budden – No Church in the Wild Lyrics on Rap Genius
Meaning
Joey says, nothing is what it really seems. Even liars can say the truth, and some who look like a sheep, can be a wolf.

Also, a sinner giving a gospel would offer some great insight, for he would be able to offer advice from the realm of his learning from experience.
To help improve the meaning of these lyrics, visit "No Church in the Wild" by Joe Budden Lyrics and leave a comment on the lyrics box