What indicates that christianity and judaism influenced the development of islam?

Islam shares a lot of believe with Judaism and Christianity-- such as the belief in one god, the belief in the same prophets, and all three religions branched from the same root and share common core values. 

Communicating with the dead was common, it wasn’t seen as bizarre or weird,” explains murch. “it’s hard to imagine that now, we look at that and think, ‘why are you opening the gates of hell? ’

Ns is has was the same point i just don’t wanna know see ya i