He's Jewish, she's Muslim, and they may be heading toward a showdown over Jerusalem's holiest site

They are activists on rival sides in the struggle for the plaza that is Jerusalem’s holiest and most contested spot. Madeline Issa calls it the Al Aqsa Mosque. Rabbi Yakov Idels calls it the Temple Mount.

Both have been scarred by events at the contested Old City esplanade, but their devotion to...