At the end of this week's parsha, the Torah recounts how Aharon and Miriam spoke against their brother Moshe. Despite the criticism leveled against him, the Torah tells us, "And Moshe was exceedingly humble (anav), more than any person on the face of the earth" (Bamidbar 13, 3). Rashi translates "anav" as "modest and tolerant". Moshe tolerated their criticism and did not get angry.
Rav Wolbe writes (Alei Shur vol. II pg. 214, 216) that tolerance is an essential virtue that is important in all our interpersonal relationships. As the Alter of Kelm writes, "How great it would be if we could habituate ourselves to act with tolerance, for it is the root of all middos and qualities and the source of serenity."
In addition to the tolerance a person must show toward others, one must also be tolerant of himself. We are all looking to grow and become better, but we constantly encounter difficulties. Sometimes we feel that the yetzer hara is out to stop us at all costs, sometimes we lose our drive to continue and sometimes we forget where we are headed. A person who lacks patience in his avodas Hashem will give up or get depressed; and there is nothing more detrimental to avodas Hashem than depression.
We think, "If only I would be able to daven the entire Shmoneh Esrei with kavanah, my whole day would look different." Or, "If only I would be able to rectify my negative middos, I would be a different person altogether." Although these musings might be true, nevertheless, we must bear in mind an important Medrash. Chazal tell us (Shemos Raba 34, 1) that Hashem does not expect from a person more than he can handle. Hashem knows our limitations and the impediments that stand in our way, and therefore, does not expect us to turn around our lives in a day, week, month, year, and sometimes even many years. We must remember that one who "grabs" too much will be left with nothing, while one who grabs a little will retain what he has grabbed.
The Vilna Goan expresses this idea in his explanation of the following pasuk in Mishlei (19, 3). "A man's foolishness corrupts his way, and his heart rages against Hashem." Sometimes a person begins studying Torah or serving Hashem and then stops because it became too difficult. He feels that Hashem is not assisting him in his endeavors and he becomes angry at Hashem for abandoning him. However, this person caused his own downfall since he jumped ahead in his avodah much too quickly and did not pace himself properly. Had he slowed his pace, Hashem would have assisted him in his avodah.
Tolerance is not merely a virtue to be exercised post facto when we realize that we haven't accomplished all that we planned. It is a middah that we must bear in mind when charting our course of actions. If we realize our limitations and are truly cognizant of our present spiritual level, we will succeed in advancing in our avodas Hashem at the proper pace, thereby achieving lasting changes for the better.