Jesus was the greatest law preacher who ever lived. Yet He never preached the law to non-Jews and He didn’t preach it after the cross.
Jesus’ law ministry reached its fulfillment on the cross. The law-keeping covenant has come and gone. The new covenant of grace, in contrast, is eternal. As we will see, Jesus’ revelation of grace is as important today as it ever was.

“We should do everything Jesus said,” is one of the most dangerous and thoughtless doctrines you’ll ever hear. And you’ll only hear it from hypocrites. I guarantee you that those who say we must do everything Jesus said aren’t doing everything He said themselves. Jesus said, “Be perfect” (Mt 5:48). If you are not perfect, then you have no business demanding perfection from others.

Jesus preached words that the whole world needs to hear but you are not the whole world. Some of what He said was meant for other people:

Jesus called the Pharisees sons of hell (Mt 23:15). You are not a son of hell! So why would you heed words meant for the sons of hell?
Jesus also told the Pharisees they belonged to their father the devil (John 8:44). You belong to your Father in heaven (1 Jn 3:1). So why would you heed words intended for the devil’s children?
Jesus even preached to the devil (Lk 4). Are you the devil? Then you should not assume that words directed to the devil were meant for you.

Some of what Jesus said was meant for another time. For instance, Jesus preached the law to those born under the law. Since you are not under law, the law that Jesus preached to them is not for you. If you think you must keep the law to be righteous/blessed/holy/forgiven, then you have set aside grace and Christ died for nothing.

http://becomehealed..com/2013/05/disciples-or-pharisees.html