Was Abraham a Gentile or a Jew? I heard that he was first a Jew, but I also heard that He was a Gentile before and then a Jew.
"Does this blessedness then come upon the circumcised only, or upon the uncircumcised also? For we say that faith was accounted to Abraham for righteousness. How then was it accounted? While he was circumcised, or uncircumcised? Not while circumcised, but while uncircumcised. And he received the sign of circumcision, a seal of the righteousness of the faith which he had while still uncircumcised, that he might be the father of all those who believe, though they are uncircumcised, that righteousness might be imputed to them also, and the father of circumcision to those who not only are of the circumcision, but who also walk in the steps of the faith which our father Abraham had while still uncircumcised" (Romans 4:9-12).
The word "Gentiles" just means "nations." It is typically used to refer to all the nations other than the nation of Israel.
"Israelite" refers to the people who descend from Israel. The people of Israel did see Abraham as their founding father. "They answered and said to Him, "Abraham is our father." Jesus said to them, "If you were Abraham's children, you would do the works of Abraham"" (John 8:39). But this is because of the promises made to Abraham, which were passed down to Isaac, and then to Jacob who was also called Israel. However, Israel's laws were not established, however, until Moses lead the people out of Egypt. So Israel did not come to be a nation until over 600 years after Abraham.
The nation of Israel divided under Rehoboam. The northern kingdom of ten tribes remained known as Israel. The southern kingdom, essentially consisting of the tribe of Judah, was known as Judah. By the time of the captivity the people became known as the Jews (I Kings 25:25; Ezra 4:12). Even though all the Israelites were released from captivity by the Medo-Persians, the name Jews stuck with the people and that is what we see them predominately called in Jesus' day.
Thus Abraham was not an Israelite because that came through his grandson. He definitely wasn't a Jew because that lineage came through his great-grandson. Abraham did enter into a covenant with God that eventually led to the founding of Israel, but he lived before that time. Paul's point in Romans is that Abraham was called righteous before entering the covenant; therefore, proving that people outside the covenant of circumcision could be saved.
Thank you so much for your immediate response. The information you gave was very useful and cleared all my doubts. Thank you again.