The Cow - 2:140
"Do you claim that Abraham, Ishmael, Isaac, Jacob and their descendants were Jews or Christians? Say: "Do you know better or Allah? Who is more unjust than he who conceals what Allah has revealed? Allah is not heedless of what you do."
The truth about Prophet Abraham and his progeny:
The Family Of Imran/3:65
O people of the Book, why do you dispute about Abraham, when the Injeel and the Torah were sent down after him? Do you not use your intellect?
The Family Of Imran/3:66
You argue about matters about which you have knowledge! But how can you argue about something about which you have no knowledge? You may not know, but Allah knows.
The Family Of Imran/3:67
Abraham was neither a Jew nor a Christian; he was a monotheistic Muslim. He was never of those who associate partners.
The Cow/2:133
"If you had been witnesses when Jacob died. He asked his children, "Whom will you serve after me?"They said, "We will serve the only God, the God of your God and the God of your fathers Abraham, Ishmael and Isaac, and to Him we are the submissive ones."