The boundaries of Moses' Law
The other day I was cruising atheist sites and saw misinformation on Old Testament Law. There was an attempt to demonstrate inconsistency by citing one law that Christians observe and then quoting another law that Christians don't observe.
Confusion is common - even Christians can mistakenly overstate the function of the Mosaic Law - but this topic doesn't need to be confusing. Jesus is quite clear on the boundaries the law resides in.
1. The Beginning of the Law: Exodus 20. The Law of Moses is a central part of our Old Testament, represented by the commonly known 10 Commandments, and served as the contract (or testament) between the Israelites and God. The 613 commandments found in Exodus, Leviticus, Numbers, and Deuteronomy each serve in one of three functional categories: Ceremonial Laws, which regulated worship and consecration (think of sacrifices, days of worship, priestly functions), Civil Laws, which governed society and community (criminal penalties, handling disputes, property and family matters), and Moral Laws, which shaped behavior (stealing, adultery, dishonesty, immorality, etc.).
2. The PURPOSE of the Law: providing a way to connect with God by dealing with our sin problem. The sacrificial system provided an imperfect yet illustrative avenue of faith: a recognition that the everyday sins we commit penalize us to an eternity of punishment but God's provision of forgiveness through faith in His sacrifice. The animal sacrifice prescription was God's temporary measure to prepare humanity for the Messiah — the perfect and sufficient sacrifice for sin — Jesus Christ's death on the cross.
3. The END of the Law: John the Baptist's preaching. Jesus Christ fulfilled the requirements of the sacrificial system through the cross; Jesus specifically stated that the requirements of the Old Testament law ended at the preaching of John the Baptist: "The law and the prophets were until John. Since that time the kingdom of God has been preached, and everyone is pressing into it. And it is easier for heaven and earth to pass away than for one tittle of the law to fail." (Luke 16:16,17). Many of the Moral Laws defining righteousness and wickedness are reiterated in the New Testament, but the requirements of the Sabbath, clean and unclean foods, sacrifices and feasts have been completed; there is nothing left to be accomplished by observing them, because Jesus fulfilled every requirement for us to be forgiven and reconciled with a Holy God.
4. The Beginning of Grace: The New Testament's basis is the death and resurrection of God's perfect Son, Jesus the Christ. "For Christ is the end of the law for righteousness to everyone who believes." (Romans 10:4). Our trust in God's provision of Christ's sacrifice now provides relief from the power and penalty of sin. Instead of worshipping at a temple through a priest with a bull or goat, we gain God's acceptance and promise of heaven with a prayer to God affirming our trust in Jesus Christ as our Savior.
Ever since the ministry of John the Baptist, there is nothing to be added to Christ's sacrifice to gain God's favor and forgiveness, but aside from God's provision there is no other way to gain God's grace and mercy.