A hard concept to grasp?

One reviewer said:  "A female second messiah is a hard concept to grasp. If you are religious I would recommend suspending reality. Just enjoy the story for the fast paced thriller and brush over the religious and feminist overtures."

I'm not sure I agree with it being a difficult concept.  I'm not religious now, but I was through much of my life, and I don't know that I would have found that concept difficult.  On the other hand, the idea interested me because I grew up in a church where only men could be leaders, supposedly because Jesus and his apostles were all men.  And I thought -- what would happen if there were a possibility of a female messiah, what would these men think?  How would they react?