"There is no man on earth of such righteousness that does good and is free from sin" (Kohelet 7:20). Being human means to sin and since G-d created us as humans this cannot be all bad. We all know that a person can grow only by learning from their mistakes. And the greater the person the greater the mistakes.
"When ( asher) a leader sins" (Vayikra 4:22). Rashi quotes our Sages who, based on a play on the words asher, (when) and ashrei (blessed), comment that "blessed is the generation in which the leaders atone even for their inadvertent sins; how much more so for their willful sins". The question is not whether our leaders will sin, that is a given, but rather what will they do after they sin.
If one avoids making difficult decisions, if one is not involved in determining community priorities, one avoids many a sin. But that is not the way of leaders or leadership. Difficult choices must be made, and thus mistakes will be made, mistakes that we can all learn from.
Rashi assumes that our leaders will sin not only inadvertently, but even willfully. This too is part of being human. This is fine provided we grow from our missteps, and as Rashi notes, are not afraid to admit them. The greater the leader the harder it is to admit one's mistakes. Might not such an admission diminish them in the eyes of their followers? While this too is part of human nature, the Torah teaches that revealing one's humanity is ultimately the more effective approach.
"The people gathered ( Vayikahel ) around Aharon" (Shemot 32:1) and soon afterward they committed the sin of the golden calf. While G-d expects us to sin and perhaps even desires it to some extent, there are some sins that are so great that the opportunity for repentance is not possible. While one may truly and sincerely regret one's actions the impact is so great that it is punishment that must be our fate. Learning from our mistakes will have to come later and in changed circumstances. The sin of adultery, for example, is so severe that amends are often not possible. At times, even if the couple agrees to forgive and forget, they may not remain married and divorce is forced upon them. Any lessons to be learnt will have to be applied to their next marriage.
Such would appear to be the sin of the golden calf. When the Jewish people rejected the G-d of history, the G-d of revelation, the only apparent option was for G-d to destroy them (32:10).
Yet soon afterwards we read " Vayakhel , Moshe assembled the entire community and said to them: These are the words that G-d has commanded for you" (35:1). G-d's readiness to accept genuine teshuva is much greater than we could have imagined. Even after such a heinous act G-d was ready to re-establish a bond, possibly even a stronger bond with the former sinners. The same nation that gathered ( Vayakhel ) together to build the golden calf now gathers ( Vayakhel ) to re-establish their bond with G-d. To attest to that ongoing relationship even after such a terrible sin, the Torah repeats the long and detailed instructions of the construction of the Mishkan , the symbol of that relationship.
In restating the command to build the Mishkan the Torah begins with the laws of Shabbat, laws we have seen many times before. Although our Sages derive from these verses that construction of the Mishkan was to be halted for Shabbat (Rashi, 35:2), it seems that there is an additional reason for Shabbat to be mentioned here. It is Shabbat more than any other mitzvah that attests to our ongoing relationship with G-d. It attests to our belief that it is G-d who is the ultimate creator. Furthermore, Shabbat testifies to the G-d of history, Who redeemed us from Egypt . The importance of Shabbat is such that the command regarding its observance was actually given prior to our arrival at Sinai, at Mara (Rashi 15:25). With the sin of the golden calf necessitating that our relationship to G-d be reestablished the Torah begins with the laws of Shabbat.
Shabbat allows us time to reflect on and analyze our activities during the week. Reflection is the first step in the teshuva process, as we strive to ensure the impact of Shabbat will sustain us through the coming week.