The entire Bene Gesserit order is founded on trying to manipulate genetic lines to produce an individual who is their prophesized male messiah. Paul appears to be a possible candidate, but great risk is attached to the prophecy, and so far all potential male candidates who have tried to reach the Kwisatz Haderach level of consciousness have died. This emphasizes how high the stakes are and just how special the prophesized messiah will be, as he will do what no other man has done before him.