to completely plagiarize a previus answer and addd to it:
You need to go a few verses after to Qur'an 3:67 to get the rest of the story, which is detailed in in the book Zad al-Ma'ad by Ibn Qayyim al-Jawziyya (زاد المعاد في هدي خير العباد الإمام شمس الدين أبي عبد الله ابن القيم الجوزية) among others.
Quoting from Zad al-Ma'ad with my own translation so treat with care (p. 550-558):
إن رسول الله صلى الله عليه وسلم كتب إلى أهل نجران: باسم إله إبراهيم وإسحاق ويعقوب، أما بعد: فإني أدعوكم إلى عبادة الله من عبادة العباد، وأدعوكم إلى ولاية الله من ولاية العباد، فإن أبيتم فالجزية
The Prophet wrote to the people of Najran: In the name of the God of Ibrahim (Abraham), Is'haq (Isaac) and Ya'qoub (Jacob), I invite you to worship Allah instead of worshiping his slaves, and to be worthy of Allah rather than his slaves, or to pay jizyah if you decline.
Refer to Qur'an 3:64.
Sixty Najrani Christians went to visit the Prophet in Medina, as a result, with multiple debates taking place over several days. Those events were co-attended by rabbis from the Jewish tribes living in Medina at the time. In one of the multiple discussions that took place, the Jewish rabbis claimed that Ibrahim (Abraham) was Jewish, and the Najrani Christians claimed that Ibrahim was Christian:
حدثني سعيد بن جبير وعكرمة عن ابن عباس قال: اجتمعت نصارى نجران وأحبار يهود عند رسول الله صلى الله عليه وسلم فتنازعوا عنده فقالت الأحبار: ما كان إبراهيم إلا يهوديا، وقالت النصارى: ما كان إلا نصرانيا، فأنزل الله عز وجل فيهم
يَاأَهْلَ الْكِتَابِ لِمَ تُحَاجُّونَ فِي إِبْرَاهِيمَ وَمَا أُنْزِلَتِ التَّوْرَاةُ وَالْإِنْجِيلُ إِلَّا مِنْ بَعْدِهِ أَفَلَا تَعْقِلُونَ - هَاأَنْتُمْ هَؤُلَاءِ حَاجَجْتُمْ فِيمَا لَكُمْ بِهِ عِلْمٌ فَلِمَ تُحَاجُّونَ فِيمَا لَيْسَ لَكُمْ بِهِ عِلْمٌ وَاللَّهُ يَعْلَمُ وَأَنْتُمْ لَا تَعْلَمُونَ - مَا كَانَ إِبْرَاهِيمُ يَهُودِيًّا وَلَا نَصْرَانِيًّا وَلَكِنْ كَانَ حَنِيفًا مُسْلِمًا وَمَا كَانَ مِنَ الْمُشْرِكِينَ
فقال رجل من الأحبار: أتريد منا يا محمد أن نعبدك كما تعبد النصارى عيسى ابن مريم؟ وقال رجل من نصارى نجران: أوذلك تريد يا محمد وإليه تدعونا؟ فقال رسول الله صلى الله عليه وسلم: معاذ الله أن أعبد غير الله، أو آمر بعبادة غيره، ما بذلك بعثني ولا أمرني، فأنزل الله عز وجل في ذلك
مَا كَانَ لِبَشَرٍ أَنْ يُؤْتِيَهُ اللَّهُ الْكِتَابَ وَالْحُكْمَ وَالنُّبُوَّةَ ثُمَّ يَقُولَ لِلنَّاسِ كُونُوا عِبَادًا لِي مِنْ دُونِ اللَّهِ وَلَكِنْ كُونُوا رَبَّانِيِّينَ بِمَا كُنْتُمْ تُعَلِّمُونَ الْكِتَابَ وَبِمَا كُنْتُمْ تَدْرُسُونَ
ثم ذكر ما أخذ عليهم وعلى آبائهم من الميثاق بتصديقه، وإقرارهم به على أنفسهم ، فقال
وَإِذْ أَخَذَ اللَّهُ مِيثَاقَ النَّبِيِّينَ لَمَا آتَيْتُكُمْ مِنْ كِتَابٍ وَحِكْمَةٍ ثُمَّ جَاءَكُمْ رَسُولٌ مُصَدِّقٌ لِمَا مَعَكُمْ لَتُؤْمِنُنَّ بِهِ وَلَتَنْصُرُنَّهُ قَالَ أَأَقْرَرْتُمْ وَأَخَذْتُمْ عَلَى ذَلِكُمْ إِصْرِي قَالُوا أَقْرَرْنَا قَالَ فَاشْهَدُوا وَأَنَا مَعَكُمْ مِنَ الشَّاهِدِينَ
The Christians of Najran and the Jewish rabbis gathered at the Prophet's. They argued with the Prophet, with the rabbis claiming that Abraham was a Jew, and the Najrani Christians claiming that he was a Christian. Allah revealed:
O People of the Scripture, why do you argue about Abraham while the Torah and the Gospel were not revealed until after him? Then will you not reason? Here you are - those who have argued about that of which you have [some] knowledge, but why do you argue about that of which you have no knowledge? And Allah knows, while you know not. Abraham was neither a Jew nor a Christian, but he was one inclining toward truth, a Muslim [submitting to Allah ]. And he was not of the polytheists. (Qur'an 3:65-67)
A rabbi then asked the Prophet: "Do you want us, Muhammad, to worship you as the Christians worship Jesus son of Mary?" A Najrani Christian said: "Is this, Muhammad, what you are inviting us to?" The Prophet said: "I forbid myself to worship any other than Allah, or to command others to worship any other than Allah". Allah then revealed:
It is not for a human that Allah should give him the Scripture and authority and prophethood and then he would say to the people: "Be servants to me rather than Allah," but [instead, he would say]: "Be pious scholars of the Lord because of what you have taught of the Scripture and because of what you have studied." Nor could he order you to take the angels and prophets as lords. Would he order you to disbelief after you had been Muslims? (Qur'an 3:79-80)
Then the Prophet reminded them of the covenant of the prophets:
And when Allah took the covenant of the prophets, [saying], "Whatever I give you of the Scripture and wisdom and then there comes to you a messenger confirming what is with you, you [must] believe in him and support him." [Allah] said, "Have you acknowledged and taken upon that My commitment?" They said, 'We have acknowledged it." He said, 'Then bear witness, and I am with you among the witnesses." (Qur'an 3:81)
Allah revealed to the Prophet that Ibrahim was neither Jewish nor Christian (Qur'an 3:67), but a Muslim, and that the Torah and the Gospel were revealed after his time, so he could not have followed either (Qur'an 3:65).
The fact that the Qur'an was revealed after Ibrahim is irrelevant since the term "Muslims" does not refer solely to followers of Qur'an or Prophet Muhammad, but to followers of Allah and his message at the time (Qur'an 22-78). According to the same chapter, the most worthy of Ibrahim are Ibrahim's followers and the followers of the Prophet and those who believe in Allah and his messages (Qur'an 3:68), all of which are called Muslims according to Islamic teachings (submitting to Allah), irrespective of which time period they belong to, or which scripture they follow. In other words, true followers of Issa would be worthy of Ibrahim, and would be called Muslims, too. The Qur'an has numerous references to people prior to the revelation of the Qur'an being called Muslims, e.g., followers of Issa in Qur'an 3:52, Ibrahim and his sons and grandsons in Qur'an 2:132-133 and in Qur'an 2:128, Nooh (Noah) as in Qur'an 10:71-72, etc.
Being called a Christian, on the other hand, is restricted to a follower of Jesus Christ and his teachings (according to Christianity); and being called a Jew is restricted to being a follower of Moses and his teachings, having Jewish ancestry, or being People of God (according to Judaism).
On another note, the tafsir by Muhammad ibn Ya'qub al-Firuzabadi, although it is being attributed to Abdullah Ibn-'Abbas, there is uncertainty about its attributions and authenticity of multiple hadiths in it (Al Tafsir). The book has a huge wealth of knowledge, but one needs to be able to discern authenticated from unverified references.
to add to this,
Dictionary definitions of a “Jew” include “a member of the tribe of Judah,” “an Israelite,” “a member of a nation existing in the land of Israel from the 6th century B.C. to the 1st century A.D.,” “a person belonging to a continuation through descent or conversion of the ancient Jewish people,” and “one whose religion is Judaism.”
According to rabbinical Judaism, a Jew is one who has a Jewish mother or one who has formally converted to Judaism. Leviticus 24:10 is often cited to give this belief credibility, although the Torah makes no specific claim in support of this tradition. Some rabbis say that it has nothing to do with what the individual actually believes. These rabbis tell us that a Jew does not need to be a follower of Jewish laws and customs to be considered Jewish. In fact, a Jew can have no belief in God at all and still be Jewish based on the above rabbinical interpretation.
Other rabbis make it clear that unless the person follows the precepts of the Torah and accepts the “Thirteen Principles of Faith” of Maimonides (Rabbi Moshe ben Maimon, one of the greatest medieval Jewish scholars), he cannot be a Jew. Although this person may be a “biological” Jew, he has no real connection to Judaism.
to be a jew 1 you need to be from the tribe of judah right. Abraham cannot be from the tribe of judah, as judah is the son of jacob, which is the son of isaac, which is the son of abraham. So first thing to do to be a jew is to be from that tribe
according to jewfaq.com It is important to note that being a Jew has nothing to do with what you believe or what you do. A person born to non-Jewish parents who has not undergone the formal process of conversion but who believes everything that Orthodox Jews believe and observes every law and custom of Judaism is still a non-Jew,
and i said to be a jew you have to be from the tribe of judah which abraham was not.
it says the scriptures were not revealed until far after abraham, so far after abraham the scriptures were revealed so how can he be a jew as you need to be from the tribe of judah, which he wasnt, nor did he even believe in the scriptures, nor read them
the second one it mentions the gospel. To be a christian. Answer: A dictionary definition of a Christian would be something similar to “a person professing belief in Jesus as the Christ or in the religion based on the teachings of Jesus.” While this is a good starting point, like many dictionary definitions, it falls somewhat short of really communicating the biblical truth of what it means to be a Christian. The word “Christian” is used three times in the New Testament (Acts 11:26; 26:28; 1 Peter 4:16). Followers of Jesus Christ were first called “Christians” in Antioch (Acts 11:26) because their behavior, activity, and speech were like Christ. The word “Christian” literally means, “belonging to the party of Christ” or a “follower of Christ.”
according to christianity, you need to believe in the trinity, to believe jesus was god, to believe he died for your sins and believe the bible to be the word of god. The bible was far later than abraham, he could not have believed in the trinity, he didnt believbe jesus died for his sins, as he hadnt died yet according to christianity, jesus is not god according to him, nor is he a follower of christ.
the word quran doesnt need to be mentiones, cus to be a musim you dont need to follow the quran. A muslim is one who submits his will to god. Of course abraham submitted his will to god, so he was a muslim. The quran doesnt need to be mentioned cus before the quran there were submitters to god, and he who submits to god is a muslim