Preach: "To exhort in an officious or tiresome manner." (All definitions are from Webster's Seventh New Collegiate Dictionary, 1967)
Therefore: To preach is to incite by argument or advice by volunteering one's services where they are neither asked for nor needed and wearing out the patience of the audience by boring them completely to the point that they are unable or unwilling to continue.
Gene Taylor is the preacher for the Centerville Road Church Of Christ in Tallahassee, Florida