From an editorial standpoint, overusing words is an obvious no-no. There are times when repetition works well for dramatic effect, of course, but it’s usually better to eliminate words or phrases that appear more than once or twice in a paragraph.
That said, I’m glad the Apostle Paul wasn’t fixated on editing rules when he wrote the first chapter of 2 Corinthians. In the space of six sentences, he used some variation of the word comfort no less than nine times, including four mentions in these familiar verses: