Hebrews 7:12 says, 'For the priesthood being changed, of necessity there is also a change of the law.' The entire book of Hebrews is an explanation of the superiority of the New Testament over the Old Testament. It contains better promises, a better covenant, better hope, a better priesthood, and is based on a better sacrifice. In Hebrews 7:12 the writer is making the point that since the priesthood has changed and Jesus is now the ever-living High Priest for everyone, it should be obvious that the law by which the priesthood operates has also changed. This simply means that we are no longer under the ritual of the law of Moses but can now come to God in a 'new and living way' (Hebrews 10:19-20). Jesus is the way! He has replaced the law of Moses as the pathway to God.