This is my observation as a layperson: I think God uses the personality (as it is being sanctified!) of the person who is preaching. A quiet, scholarly type person is just as much used by God as is the charismatic (outgoing) person or the one prone to a dramatic speaking style. In any case, it is God who gives the ability to teach and preach and it is the Holy Spirit who illuminates the word. While this is not a perfect analogy, a similar situation exists in the scriptures where Paul has a style that is different from David.

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JWithnell
Member Bethel OPC
Virginia