The Main Weapon is Prayer

Rebbe Nachman of Breslov, zt"l, teaches that our main weapon to overcome bad behaviors is prayer. This is why we daven extra during the month of Elul. Sincere prayer is the most powerful way to rectify our sins.
Rav Tzvi Hirsch Zaks, zt”l, recounted that one of the students of his grandfather, the illustrious Chofetz Chaim, zt”l, noticed that his Rebbe would often slip out of his house every night after midnight, enter a shul, and remain there for many hours. This student burned with curiosity: what could his Rebbe be doing alone in the shul? Learning? Surely he could do that at home. His mind abounded with possibilities… Tikkun chatzos? Perhaps he was davening heartfelt prayers for the sick and unfortunate?
Finally he could no longer stand the pressure of his curiosity and he hatched a plan to find out what the Chofetz Chaim was actually doing after midnight alone in the shul. He entered the women’s section of the shul somewhat before midnight so he would be able to observe the area easily. He would be unnoticeable, but would surely see and hear everything that the Chofetz Chaim did.
Around midnight, the Chofetz Chaim entered the shul, proceeded to the front, and threw open the holy ark. He began to cry profusely. In a voice chocked with tears he cried, “Ribono Shel Olam! Yisroel Meir is a kohein and kohanim are easily angered. So please, Hashem, help me overcome my tendency to get angry…”
The Chofetz Chaim stood there for hours petitioning Hashem over and over again to protect him from anger—the cause of so much destruction and machlokes!
(Story from:שאל אביך ויגדך, חלק ג' ע' קס"ז)