Here the pharisees are more concerned with Jesus breaking one of their rules than whether or not someone's life is changed. The reason that the pharisees were so against Jesus is that Jesus was a threat to their way of life. The pharisees had respect and power because people listened to them about God. If people started listening to jesus instead, then all of their power would be gone. Basically they were crazy jealous of Jesus. jealous enough to plan out killing him.

Mark 3:1-6