With the arrival of Jesus Christ on the scene, there was no need for the agreement—the Old Covenant—to continue. This does not mean God's laws are obsolete, but that the agreement between God and the physical children of Abraham is no longer necessary because there is now a New Covenant that far exceeds the old one in terms of promises and benefits, in addition to the fact that God has divorced Israel (Isaiah 50:1; Jeremiah 3:8). No longer is property or homeland a goal but the entire earth. No longer is physical health an aspiration but a new spiritual body that is not subject to disease or decay.
Christians are not bound by the Mosaic covenant, that "guardian" that was intended to keep Israel pointed in the right direction until there was a means by which they could receive a new heart and have access to God through the Holy Spirit. So the Old Covenant is not what we have agreed to, but it should be noted that the laws contained in "the law" (Pentateuch) still have paramount merit, because they are an extension of God's character and mind. There is no need for animal sacrifices, because Christ has fulfilled that, but there are still many lessons that can be learned through contemplating those laws. Other laws, such as the purity laws, may indeed still have a physical application as well as a spiritual one. God recorded those statutes and judgments for our admonition (I Corinthians 10:11), and they help us to see how God lives when we examine them in the light of Christ's ministry and teaching. Obeying them does not make us righteous in God's eyes or earn us salvation, but "a good understanding have all they that do His commandments" (Psalm 111:10). By them, we can learn to live as God lives (Matthew 5:17).
David C. Grabbe