"... avoid strivings... about the law... "
Certain professing Christians think this scripture means that we should avoid attempting to understand or explain scriptures about the law or genealogy and avoid anyone who wants to discuss it because it benefits no one.
"So likewise... when ye... have done... what was commanded... you say 'We are unprofitable. servants, we have done... our duty.'"
Certain Christians think this scripture means we should not act like servants, but rather like gods who take charge in order to be more powerful in the Spirit.
"... mark those who cause divisions and offences... and avoid them."
Many Christians think this scripture means that we need to take note of the Christians who get easily offended by the sins of others.