Today's Parsha discusses the tragedy of the sin of the spies. When the evil report was heard, the Torah tells us that the people cried that entire night. The commentators tell us that Jashem said," You cried for nothing. Now I will give you a reason to cry every year on this date. The date, of course was the 9th of Av, the original 9/11. ( It was on the ninth day of the eleventh month.) This was the day when many tragedies occurred in our history aside from the destruction of the two Temples.
We are to learn a lesson from this whole story. It is a terrible thing for a person to be filled with self-pity. We must always learn to look at the bright side of every situation. The idea of crying for nothing has very detrimental effects on us.
Negativity has no place in Judaism. We are to work on ourselves to drive away all of our negative thinking. It is interesting that the ארחות צדיקים views worry as the opposite of happiness.
The lesson of the spies is to always look at the positive and that we must be grateful for what we have-not what we don't have. And we must never forget that Hashem is watching over us and will never forsake us.