For 15 centuries the Jews had followed the Mosaic Law, the Levitical priesthood, and all the practices associated with them. Now, Jesus has come to change all these things and institute new practices centered around Him. All these old things are no longer necessary, and the center of their faith should no longer be with old practices, but instead, be concentrated on the words of Jesus and His ministry. Giving up these long-established traditions is hard.
Paul is telling them that a new revolution has taken place and that an entirely new manner of life has been set