Life is accompanied by a constant flow of decisions and choices that determine a person’s path as he makes his way through life. Who among us has never entertained the thought of what would have happened had he chosen a different direction? Thoughts concerning our ability to change the past have always weighed heavily on the minds of many people, as evidenced by the significant number of movies dealing with this very theme. One famous example is “Back to the Future,” where the protagonist travels through the past, present and future, and over the course of his adventure, he interferes with his personal and family history.

But is it so clear that our lives move progressively forward and do not allow us to change or correct the past? Indeed, the wisest of all men – King Shlomo – remarked (Kohelet 1:9), “That which was done can never be taken back.” However, the month of Elul and period of the Yamim Noraim (High Holidays) seem to lead us towards a slightly different answer.

The Rambam writes in Hilchot Teshuva (3:6): “Just as a person’s sins and merits are weighed at the time of his death, similarly, each year, the sins of everyone on earth are weighed against his merits on the festival of Rosh Hashanah. One who is found to be meritorious is sealed for life, and one who is found to be sinful is sealed for death. And the beinoni [person whose merits equal his sins] – he is held in abeyance until Yom Kippur. If he performs teshuva, he is sealed for life; otherwise, he is sealed for death.”

The question arises, why is it that only teshuva can save the beinoni, and not mitzvot and good deeds? After all, had his merits exceeded his sins, he would have earned a favourable judgment. So why can’t he earn a favourable judgment on Yom Kippur by tilting the scales in his favour through the performance of more mitzvot, thereby acquiring more merits? Perhaps one might answer that after Rosh Hashanah, his merits count towards the following year’s account, and are thus of no avail to him regarding the previous year’s judgment. But if this is the case, then why does his teshuva help him after Rosh Hashanah?

From this passage in the Rambam, we can extract a very important concept regarding teshuva. Teshuva is not merely another merit that a person adds to his total. It rather eliminates his sins retroactively. A person who performs teshuva erases his sins of the past from the record completely, as if they never occurred in the first place. Therefore, the original accounting that was done becomes null and void, as the sins no longer exist. Teshuva does not add more merit and thus weigh down the scales in the person’s favour. It rather nullifies the sins, such that the person’s judgment is naturally decided in his favour, as the scale of sins has been emptied. This is the unique power of teshuva. It not only purifies the individual from this point on, but rather purifies him retroactively, as well, and makes it as if he had never sinned at all.

This perspective on teshuva, as a journey back in time, clarifies for us yet another feature of the halachot of teshuva. Reish Lakish famously commented (as cited in the Gemara, Masechet Yoma 86b), “Teshuva is great, for [through teshuva] intentional violations are transformed into merits.” The Gemara explains that when a person repents genuinely and out of love (as opposed to fear); teshuva has the power to turn even his wilful violations into merits. At first glance, this seems very perplexing. Clearly, it would have been far better had the wrong never been committed. How, then, can it now transform into something positive, capable of yielding merit to the perpetrator? The answer is that, as we have seen, teshuva has the capacity to return to the past and change the sinner’s personal, past history, and transform the negative act committed into a positive event, thereby exchanging sins for merits.