Correct me if im wrong about christianity islam and judiasm?

after looking up a lot of things there were a few sources claiming that all of these religions believe in the same god. the "main" difference is the choice in phrophets or messiahs. islam is mohammed, christianity is jesus and the first coming has yet to come for the jewish. i think that is somewhat true because they both have roots in judism. and please dont waste my and your time if you are here to be a . im not opposing religion just curious