Zechariah - Chapter 13
The Conversion Movement
In the future, a spring will flow in Jerusalem, so that the residents will not have to leave the city to immerse for matters of ritual purity. When that happens, G-d will have eradicated idolatry so thoroughly that people will not even speak the names of false "gods." G-d will remove false prophets and even the evil inclination. If a person prophecies falsely, everyone will know it intuitively. They will be so close to G-d that even the false prophet's own parents will say that he deserves to die for such an affront. The false prophets will be so ashamed that they will discard the identifiable clothing of their profession and deny their occupation altogether.
G-d calls His sword against the emperor of Rome. When He strikes him down, his subordinate rulers will scatter and their officers will fall. One-third of the non-Jews in the land (Israel? The world?) will be part of a mass conversion movement. G-d will test the sincerity of these converts. Those who pass, He will call His people and they will call Him their G-d.