"For behold, in that day that they shall rebel against me, I will curse them even with a sore curse, and they shall have no power of thy see except they shall rebel against me also."
God protects His people, making it possible to distinguish the enemies of the servants of god. Even making it so that if the people are dong the right things the enemy shall not prevail against the righteous. But if the righteous fall and don't listen to the words of God, then they shall be reminded as needed.
God Himself protect His people. Happen look see difference Group1 follow God Group2 not. People themselves do right enemy overcome not. If right people fall stop listen God, Himself allow remind if need.