If Christ came to free absolve people from keeping the Law as antinomians claim, then passages like Isa. 2:3, Mic. 4:2, and Zech. 14:16-19 shouldn't exist. Those passages say the Law will be kept as a way of life by everybody who lives during the Millennium. Christ isn't going to come back and magically make the world be peaceful and adhere to biblical Christianity. That will become a reality because everybody will have been taught to keep the Law.
The Bible also shows that Christians who have already been faithfully keeping the Law throughout the 7 Church eras will be their teachers:
"But you are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light;" - 1 Pet. 2:9
"and has made us kings and priests to His God and Father, to Him be glory and dominion forever and ever. Amen." - Rev. 1:6
"And have made us kings and priests to our God; and we shall reign on the earth.” - Rev. 5:10
As the OT shows, the priests and rulers were held more responsible for keeping the Law than the common Israelites because they were supposed to be the educators and primary examples of what holy living looked like. And as the above NT passages show, God doesn't expect any less from true Christians. When Christ returns and Christians are truly reborn as literal God Beings(contrary to what Orthodox Christianity teaches, this is what Christ actually meant when He said a person had to be born again to see the Kingdom of God), a world that has just been freed from Satan's influence will need teachers to guide them and kings that will properly rule over them.
In order for God to trust anyone with that kind of authority in His Kingdom, He has to first know beyond a shadow of a doubt that the individual Christian will remain loyal to His laws in their physical lives. The Law is how God has been making man in His image throughout human history, and the Law is how He will remake the entire universe in His image once His plans for this planet are complete. There won't be any Lucifers in His Kingdom teaching lies about how Christ supposedly came to abolish the Law.