Jesus was calling on the Pharisees to examine their priorities: mercy is more important than burnt offerings, human need is more important than silly rules, compassion is more important than tradition.
Our own lives are regulated by laws and traditions. Under normal circumstances we are obligated to obey these laws and observe these customs. But such things are servants, not masters. They are intended to serve human good. When they stand in the way of human good, they must be ignored or changed.