Prayers, Tears and Feelings can have considerable cosmic influence

• If Noah had asked G-d for mercy, there would have been no flood (Kedushat Levi : Noach, first article)
• On three occasions G-d accedes to Moses’ requests not to destroy Israel  (Exodus 32, Numbers 14, Numbers 16)
• Jeremiah tells the exiles: If you had cried even once in Zion, you would not have been exiled (Midrash Tehilim 137:1)
• Rabbi Meir’s prayer leads to the repentance of criminals (Babylonian Talmud, Brachot 10a)
• Rabbi Eliezer’s sorrow about being shunned wreaks destruction, which is only contained by Raban Gamliel’s prayer. (Babylonian Talmud, Baba Metziah 59b)
• “The blessing of an ordinary person should not be taken lightly…The curse of an ordinary person should not be taken lightly” (Babylonian Talmud, Megilah 15a)
• The unintended tear of a neglected wife leads to the death of her husband (Babylonian Talmud, Ketuvot 62b)
• “For the upper world is not stirred to act until an impulse is given from the lower world.” (Zohar, Lech Lecha, 77b)
• The deeds or repentance of an individual may save the whole world from destruction (Maimonides, Mishnah Torah, Hilkhot Teshuvah, 3:3-4; Babylonian Talmud, Kiddushin 40b). 
• “One tear, one prayer can change the course of events.” (The Baal Shem Tov, see Eli Wiesel, Souls on Fire, p. 26)