You gon' be the priest, and I'mma be the preacher
The difference between a priest and a preacher is that a priest is generally more of a top-down, word-of-god leader, in that he will tell his flock what their duty is, while a preacher is more focused on the power that the people have, emphasizing their strength over their duty.
In other words, a preacher is more inspiring, while a priest is more grounding. This highlights the difference in the styles of B.o.B. and Nicki Minaj.
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