The Mosaic contract is no longer in force. It has been replaced for everyone, including Jews, by the new contract. The new contract is a new enterprise. Gentiles were never under the old contract. Now, Jews and Gentiles alike who put their faith in Jesus are under the new contract.
Does that mean we can go around murdering people because we’re not under the Mosaic Law? No. The obligation not to murder is universal and should be in any law. Just as our law does, the Mosaic Law included universal moral principles. So we are obligated to follow those moral rules, not in virtue of them being in the Mosaic law, but because they are universal for all people. The Mosaic law included universal moral rules and rules that were limited to the nation who lived under that contract. We have to distinguish between these as we consider how we relate to the Mosaic covenant now.
Universal moral obligations from the Mosaic Law are repeated in the New Testament. The things that no longer apply to us are not repeated in the New Testament. It’s exactly like being in a separate state.
For example, love God with all your heart and love your neighbor as yourself are in both the Old and New Testaments. This is a summary statement in the New Testament. Part of it was in response to the Jews. It was hard to keep all the laws, so they decided, let's keep the most important one. There were debates between them about which law was the greatest commandment, so they asked Jesus. The purpose of finding the greatest commandment was to focus on keeping that really well and not worry so much about the others.
Jesus says, you don't have to worry about the rest of the commandments if you can fulfill these: Love your God with your whole heart, soul, mind, and strength; and love your neighbor as yourself. Then, the lawyer who raised the question, seeking to justify himself, asks who is his neighbor. Jesus responds with the parable of the Good Samaritan, which points out even your enemies are your neighbor.
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