Hebrews 7:11-12 say that God changed the priesthood from the order of Levi to the order of Melchizedek. This change necessitated the change of the laws of worshiping God.
As a Christian you died and rose with Jesus Christ. This means that the law no longer applies to you because it is only applicable to people whose sin nature is alive. You now can produce a harvest of good deeds for God. (Romans 7:1-4)
God is taking us back to how He dealt with Abraham; the commandment He has for us is to believe God, and do justice and righteousness (Genesis 18:19). So God did not remove the law and leave a vacuum, now that we are free from the law we can focus on doing righteous deeds which have the potential to eliminate sin when allowed to grow (Romans 6:11-14).
“When we were controlled by our old nature, sinful desires were at work within us, and the law aroused these evil desires that produced a harvest of sinful deeds, resulting in death. But now we have been released from the law, for we died to it and are no longer captive to its power. Now we can serve God, not in the old way of obeying the letter of the law, but in the new way of living in the Spirit.” Romans 7:5-6 NLT
Paul called the law the ministry of DEATH and CONDEMNATION (2 Corinthians 3:6-9). To the Galatians Paul said God declared that the child of the bondwoman (law) will not be heir with the child of the freewoman (Spirit) – Galatians 4:30.
Jesus introduced THE NEW COMMANDMENT (John 13:34). We are commanded to do two things: 1. Believe in the Name of Jesus Christ, 2. Walk in love toward other people as Jesus loved us. (1 John 3:23)
The law is not bad, it gets used by sin to bring condemnation which leads to death. When we preach the law we empower sin in the lives of the hearers. (Romans 7:7-13)