Christian leaders insisting on using titles, having different clothes, using assigned parking spaces, or sitting in special seats during services... These might lead to a clergy/laity distinction in the minds of their people.
I don't think it's a sin to want to be called "Reverend" or "Pastor," but it is a mistake.
Where is the biblical precedent for that?
I am a pastor, but please call me "John." I'm no better than any non-pastor.