how does this relate to the relationship between judaism, christianity and islam?

Well, There are a lot of similarities between the holy books of Judaism, christian, and Islam, whether in events or in the Characters.

The only thing that differentiate the three of them is the existence of the true savior. Unlike, the christians, Judaism does not view Jesus Christ as the promised savior. So does muslim in this matter who viewed Jesus as only one of the phropets