In the comments section of “24 Dilemma,” AC asked an interesting question that I thought was worth discussing with everybody: “If all Christians were to be elected to office…would it be right in the eyes of God to put the death penalty for...adultery (like it was in the Old Testament)?”
Just today I heard someone on the radio say he was afraid of Christians doing this very thing, so this is a real question many people have out there. To answer it, we need to think carefully about what the Old Testament Law is and what our relationship to it ought to be as Christians.
In the case of ancient Israel, God was working through a nation. He gave them a constitution that would shape their country to reflect His holiness to the world. Their perfection was demanded by the Law in order to do this (hence, the harsh punishment for its violation). This constitution (and contract with God) was the Mosaic Law in the Old Testament. But even though the Law was perfect and holy, it didn’t have the power to make the people act perfectly holy (Romans 8:3), so Israel failed to represent God well. (This is the reason for the punishment of their exile to Assyria and Babylon.)
Paul says that, though they would fail to live up to the perfect holiness it demanded, Israel was given the Law so that all the world—including those who had the perfect Law—would realize that they need a righteousness that comes from God instead of their own works because they’ll never measure up to the perfect holiness of God’s own character, which is the standard of goodness (Romans 3:19–26).
Now, in the New Covenant, God is not working through a political nation, but instead the Church is made up of people all over the world who have joined themselves to Christ (not a nation) and been made new creations who can find the power to overcome sin through the Spirit (Romans 8). All who now identify with Christ are seen by God as having died and risen with Christ. When those who were under the Law died with Him, they were released from their former contract (as all dead people are) and raised with Christ to the New Covenant (Romans 7:1–6).
We have therefore been released from the Old Testament Law; it is not a contract that God made with Christians, but with ancient Israel. The Law still instructs us as to what holiness looks like, but we aren’t under that contract, so it has no authority over us.
A political government in these times ought to keep order (according to Romans 13), but it doesn’t have a contract with God to enforce perfect holiness in order to represent God to the world. This is because God has not made that contract with any nation today; it is Christ who now perfectly represents the character of God to the world. Therefore, instituting all Old Testament laws and punishments today would be to misunderstand the purpose and authority of the contract God made with ancient Israel.
If you’re interested in hearing more detail about the relationship of the Christian to the Old Testament Law, Arnold Fruchtenbaum of Ariel Ministries has an article titled “The Law of Moses and the Law of Christ” that fills in many of the gaps I left above (you’ll need to find the title of the article on the linked page and click on it). I also recommend the book From Creation to the Cross which has an excellent chapter on the Law and covers many other theological themes in the Old Testament.