The Bible distinguishes between the house of Israel (also referred to as the lost ten tribes) and the house of Judah, or the Jews. At the time of Paul, the house of Judah was politically composed of the tribes of Judah and Benjamin, and part of Levi. A careful study of Paul's writings reveals that he uses the term "Jew" many times as a SUMMARY TERM, which also includes all the tribes of the house of Israel; for instance, Joseph (Ephraim and Manasseh), Simeon, Levi, and Reuben.
We read, in Acts 21:39, that "Paul said, I am a man which am a JEW of Tarsus, a city in Cilicia." However, in Romans 11:1, Paul explained: "I also am an ISRAELITE, of the seed of Abraham, of the tribe of Benjamin." Notice that Paul called himself a Jew and an "Israelite" -- a descendant of ancient Israel or Jacob -- and not just a Jew.
Acts 9:15 shows Paul's 3-fold mission; i.e., to bear Christ's name before GENTILES, kings and the children of ISRAEL. Here, the Bible makes a distinction between Gentiles and the children of ISRAEL -- not just Gentiles and Jews. This passage shows that the children of ISRAEL are NOT Gentiles.
In Matthew 10:5-6, the same distinction is made. We read, in the Authorized Version: "These twelve [apostles] Jesus sent forth, and commanded them, saying, Go not into the way of the Gentiles, and into any city of the Samaritans enter ye not: but go rather to the lost sheep of the house of Israel." The twelve were forbidden, at that time, to spread the gospel among the Gentiles, but they were to preach it to the house of ISRAEL -- not just the tribe of Judah, commonly referred to as "Jews." Again, we see from this passage that the children of ISRAEL (not just the Jews) are NOT Gentiles.
James defined the children of Israel in his letter as "the twelve tribes of ISRAEL." The TWELVE tribes include not just the Jews, but ALL of the tribes of Israel (compare Revelation 7:4-8). James 1:1 says: "James a bondservant of God and of the Lord Jesus Christ, to the TWELVE TRIBES which are scattered abroad."
As was mentioned, the term "Jew" in Paul's writings is, many times, a summary term for all from the house of Israel and Judah. As we saw, Paul says he is a Jew and an Israelite; Christ says that "salvation is of the Jews" (John 4:22), but Paul writes in Romans 9:3-5: "For I could wish that I myself were accursed from Christ for my BRETHREN, my countrymen according to the flesh, who are ISRAELITES, to whom pertain the adoption [better: sonship], the glory, the COVENANTS, the giving of the law, the service of God, and the promises, of whom are the fathers [Abraham, Isaac and Jacob] and from whom, according to the flesh, Christ came..."
Although the tribe of Judah is included here, the passage goes beyond the Jews and includes ALL tribes of the house of Israel. Many commentaries do not understand this distinction and equate Jews with Israelites, as if all of the tribes of Israel are "Jews." This is, however, untrue. The Jews are ONE tribe of Israel. So, it is correct that all Jews are Israelites, but not all Israelites are Jews, and none of them are "Gentiles." The law and the covenants were given to ISRAEL, not just the tribe of Judah (compare, too, Ephesians 2:12, speaking about the GENTILES who were formerly aliens from the commonwealth of ISRAEL, and strangers from the covenants of promise). The promises were made to Abraham, Isaac and Jacob, the "fathers" -- the forefathers of all of Israel, not just the tribe of Judah.
As "Jew" in Paul's writings is many times a summary term for all the tribes of Israel, the term "Greek" is many times a summary term for all Gentile nations. Please note that Paul, many times, uses the terms "Greek" and "Gentile," interchangeably. In Romans 1:16, Paul speaks about Jews and Greeks, but in Romans 2:9-10 (in the AV), in the same context, he speaks about Jews and Gentiles. (Compare, too, Romans 9:24.) At times, there might be a distinction between "Greeks" and other "Gentiles," but at other times, the term "Greek" is all-encompassing. The Ryrie Study Bible explains in a footnote to Romans 1:14: "'Greeks' -- Those who spoke Greek and who had adopted Hellenistic culture, in contrast to 'Barbarians,' who had not. However, in v. 16 'Greek' means 'Gentile.'"
In passing, we are not addressing here the additional aspect of "spiritual" Jews, that is, true Christians (compare Romans 2:28-29). It might be noteworthy, that even in that regard, the Church is referred to, in Galatians 6:16, as the "ISRAEL of God."
The letter to the Galatians says much about Jew and Gentile. One key passage is Galatians 3:28: "There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus." Here the contrast between nationalities (ethnic), between slave and free (social) and between male and female (sexual) is drawn. The first one covering nationality is restricted to either "Jew" or "Greek"--REPRESENTATIVES of either Israelites or Gentiles. Especially considering that rulership arises from the Jews, the term "Jews" is used here as a summary term for all the tribes of Israel, represented by the RULING tribe. "Greeks" served as representatives of all other nations.
When Paul speaks in his writings about "Jews," he is addressing, many times, all of the tribes of Israel. He did not mean to imply that everyone, who is not a descendant of the tribe of Judah, is a "Greek" or a "Gentile." Today, the descendants of the house of Israel can be found in the United States of America, Great Britain, Australia, New Zealand, and parts of Europe. They are not "Gentiles," but of the house of Israel. This is important to understand, if one wants to comprehend what is prophesied about their future. For more information, please read our free booklet, "The Great Tribulation and the Day of the Lord."
"You are the light of the world. A city that is set on a hill cannot be hidden."-Matthew 5:14