Doha Knight, Sorry i got you wrong, my mistake..
but i will correct you, that as per believes, and what is written in our holy book, says that Prophet Abrahim A.S was Muslim.

secondly about the sacrifice, it was Ismail A.S, who was chosen for sacrifice, as written in Holy Quraán, on which we believe. Allah Almighty took test of Abrahim A.S two times, first he got the orders to leave Ismail A.S in the area far away from the city, where now Makkah is present, and he did so,
then when the Ismail A.S grown up, then again Allah asked for the sacrifice of Ismail A.S from Abrahim A.S, which he followed again, and we are doing our sacrifice according to that.

regarding jews why they are not doing the sacrifice, i have an idea, don't know how to express, may be sometime later
or i will wait for FathimaH, may be she explain better then me