Perek 2, Mishnah 13: The greatest nechamah (comfort) comes from davening (praying). The way our davening should be, begging and asking Hashem for compassion- not: something I know I have to do, but rather would not. It is the nature of a person to give up after a while if his very best efforts appear not to bear fruit time and time again. Different types of tefillah (prayer). Living as an "ani" - a poor person, in whatever area of life that may be. What is the purpose of crying over something that happened a long time ago? The very deepest meaning of prayer. Avraham Avinu's "apparently" unsuccessful tefillah for Sdom - without Lot and his daughters there's no Dovid HaMelech. Rebbi Shimon tells us to never categorize ourselves as a rashah (wicked person). Our tears are building the "menachem" (comforter), the Moshiach.