He compares what he does to division in a family, a father against his son etc. Is Jesus encouraging family conflict? No. But what he is saying is that people shall have to make choices and that sometimes these choices will have to go against what others think and say. If we choose to follow Jesus, others may choose the opposite and no matter who it is who makes the negative choice we have to stay loyal to our beliefs. Often this shall cause conflict, but there can be no bending of the truth to please other people. The more we come to know Jesus the more total loyalty he demands.