First of all, I think we do injustice to God’s instructions in scripture — both testaments — by seeing them as merely law; arbitrary things we must do to gain His favor or to avoid obliteration. Psalm 119 saw the law as an insight into God’s deep love for us, and so did Jesus (Matthew 22:34ff). God gives us instructions for us to become more like Him, not only for our own good, but for the good of all.
Secondly, I think we understand poorly the concept that law has been supplanted by grace in the example and Person and sacrifice of Jesus Christ (John 1:17). Law is not bad, but it is insufficient to save (Galatians 3:21; Hebrews 7:11). Its time and function to lead us has past (Romans 6:14). It is now written on our hearts, which should be much softer than tablets of stone.
Third, God still has instructions for us through Christ. He repealed specific instructions through what He taught, did and suffered – rendering them obsolete: animal sacrifice, priestly tribes, sabbath observance, as examples. They were replaced by much broader, wider, more demanding, more perfect expectations: self-sacrifice, priesthood of all believers, constant spiritual act of worship, etc. But not all were specifically repealed.
Some were specifically reaffirmed. We still are not to commit murder … but neither are we to hate. We are still not to commit adultery … nor are we to look after someone not our spouse with lust, and thereby commit adultery in our hearts.
Some were left as matters of conscience and tradition, not binding on Gentiles.
And some of the 613 precepts of the law just don’t get mentioned at all.
This calls for discernment, which is the gift of the Holy Spirit, and we can ask for it.
Does God still detest divorce (Malachi 2:16) and find remarriage to the original partner detestable (Deuteronomy 24:4)? When did it stop being an abomination to Him, so that some teach it as a requirement to please Him? Does Numbers 23:19 lie about Him changing His mind?
He commands (2 Chronicles 29:25) and is pleased with worship that includes singing accompanied by instruments of music, right through the the Old Testament– see Psalm 150 for a sample. When did He change His mind about this? Why would He not express this change explicitly as Jesus does about the Sabbath? Has He ever failed to tell — no, to SHOW — us what is expected of us?
“He has shown you, O mortal, what is good. And what does the LORD require of you? To act justly and to love mercy and to walk humbly with your God.” – Micah 6:8
This article is expanded from a comment I made at Tim Archer’s blog.