Authors use repetition for several reasons, including making a point, to set a rhythm, link topics or ideas and to make discussions easier to follow. Using repetition in writing is something that still has rules and should be used with some thought instead of randomly.
In order to use repetition correctly, make sure that only key words are used and that the repetition serves a purpose. The use of redundant pairs and unnecessary words is something that can happen easily when using repetition as a style in writing. Writers should read and reread their own work, sometimes out loud, to check the flow and how the piece reads.