Is Matthew 5 only for the Jews?

Answer:

This is a variation of an argument that has been around for a while. The core of the argument is to relegate some portion (or all) of the gospels to the Old Testament to avoid applying Jesus' teaching. To see arguments against attempts to relegate all the gospels to the Old Testament, see Matthew, Mark, Luke, and John: Old Testament or New Testament?

Your friend is avoiding the extreme and saying only Matthew 5 should be considered Old Testament. However, the designation is arbitrary. Why is one chapter in a book different from the entire book? Realize that chapter and verse markings came long after the Bible was completed. Matthew 5:19 refers to the kingdom of heaven. Is this Old or New Testament? Matthew 5:22 indeed refers to the courts (the Sanhedrin Council). The courts are discussed in the Old Testament, but the Sanhedrin Council was formed after the Old Testament was completed. Matthew 5:23 refers to bringing gifts to the altar, but when Jesus gave the sermon, his audience was Jews living under the Old Testament laws. While the illustration was meaningful under the Old Testament, the principle being taught would apply to both testaments. Anger should be resolved quickly and before approaching God for worship. Is your friend arguing that Jesus' teachings about anger can be ignored?

Matthew 5-7 is one sermon given by Jesus. Why does he want to eliminate the first third of it? What about the rest of Jesus' teachings in that sermon?

Then there is the problem that James refers to Matthew 5 in his book (James 5:12 refers to Matthew 5:37). If Matthew 5 is Old Testament, then is James also Old Testament?

Yet, your friend argues against Jesus' teaching on divorce and not anger? Why? It doesn't gain him anything. Matthew 19:9 gives a similar statement to the one found in Matthew 5:32.