The God of Abraham has a Son named Jesus. Jews do not believe Jesus is the Son of God. Therefore, would it be incorrect to say Jews do not believe in the God of Abraham?
Yes, it would be incorrect. Simply because non-Christian Jews do not fully understand or accept the fullness of God’s revelation does not mean they do not believe in him. The article below was written to explain that Muslims believe in the one true God, but is also helpful for understanding how other non-Christian monotheists believe in the one true God.
Muslims Worship the One True God by Fr. Brian Harrison, O.S.