To a married woman in a desperate situation, who greatly regretted her actions:

You should not pray for a miscarriage. You should do what you have to do, and let G‑d take care of the rest. If He so wills, He can change the past for you as well. How do I know? Hear me out, step by step.

Reish Lakish was a student with a sharp, biting intellect. He was also a highway robber chief. Not simultaneously, mind you. Things changed when he met Rabbi Yochanan.

You see, Rabbi Yochanan was exceedingly handsome. When Reish Lakish saw him bathing one day in the Jordan River, he pounced upon him. Rabbi Yochanan kept his wits and told Reish Lakish, “You are so strong! If you would put that strength into Torah, you could be a great rabbi!”

Reish Lakish became Rabbi Yochanan’s pupil, and threw all his strength into his studies. Eventually he became his teacher’s study partner. The Talmud is replete with their debates, Rabbi Yochanan suggesting his ideas, and Reish Lakish ripping them apart and rebuilding on his own.

Reish Lakish died young, but he left behind many teachings—teachings that no one else could have taught, because you had to have been a highway robber to know them. Like the idea that sins can become merits.

“When a person turns himself around, regrets his past and does good, that is such a powerful act that his sins become merits.”

How on earth can sins become merits? Sins are despicable deeds in the eyes of the One who made you. So, now you regret them. How can your regret today reach back and transform something written solidly in the record of the past?

The simple answer is that some things are not written so solidly. Like the fact that you were sinning. There was an act that happened, one that you now admit was reckless, despicable and damaging on all fronts. Yes, that is a sin. But were you sinning? Where were you at the time?

Until you return, we know who you are and who you were. The act you did tells us all. But what if you undergo a transformation? What if the divine soul within you bursts out and exclaims, “I never wanted anything to do with all that! I screamed and no one heard. I was held captive and raped. It was a conspiracy of the perpetrator and this person within which You forced me to reside!”

The soul does not lie. Yes, there is always free choice. No one is ever forced to sin. But that whisper of G‑d breathing inside you, did she choose to sin? She was the innocent party, overwhelmed by the force of the coarse body in which she is entrapped, her desperate pleas ignored by the mind of a person who chose, this time, to follow the body and not the soul.

Until now, this person had never emerged. She was unknown, not even as a fetus is known within the womb or a butterfly enwrapped within its cocoon, for the deeds of the body in which she lay dormant contradicted and negated her very essence and being. But now she bursts forth as a sudden dawn, illuminating the entire landscape. And when we ask, “Who are you? From where did you come?” she replies, “I am the true core and essence of this woman. I am the pulse of her heart, the breath of her soul. I was there within her all along. And I am pure and innocent.”

Now this innocent core-essence is in control. You are no longer the body; you are that soul. In this way, the past is healed. The act was a sinful act, but you—this you that we see today—were not involved at the time. In your record, the act does not exist.

Then there is a further step: The sin exists—and it is in your merit:

“More beautiful,” our sages say, “is a moment of return and good deeds in this world than all the life of the world to come.” They were speaking of the good deeds that follow remorse over the past and return to good. Because those good deeds are performed with such passion that the light of the Shechinah in the loftiest Garden of Eden pales before them. And that is why “in the place where one who has sinned and returned stands, even the perfect tzaddik is unable to stand.”

From where comes such intense light that even the perfect tzaddik can never imagine to attain? From the passion of sin. As the energy unleashed through the fission of matter explodes in awesome force, so too the darkness that becomes light knows no containment. The tzaddik has never tapped that passion; it does not exist in her world. The sinner who has returned invests it in her every deed, in every moment of her life.

The passion that once drove an ugly sin now becomes the engine driving bursts of G‑dly light; the rope that once strangled the soul now becomes her redeemer.

That is the story through which Reish Lakish lived. The passion he had taken in assaulting innocent travelers was of a quality that Rabbi Yochanan could never have invested in even his most noble deed. An explosion of goodness out of an earnest heart is nice, but it’s not on the Richter scale of the visceral, heart-pumping, adrenalin rush of unmitigated crime. Yet now, Reish Lakish was throwing that same mind that had connived ambush into arguing fine points of halachah; that same iron fist that had caused so much harm into a caring and giving hand, open to the widow and the orphan; that same prowess of leadership that had ruled over a band of thieves into the stature of a scholar and spiritual leader of his people.

In truth, this is the only way we can explain G‑d’s actions: How does He throw His precious child into a moat of crocodiles, knowing full well the inevitability of sin? It is with a purpose, so that those sparks of passion will be redeemed and they too placed in His service. As Solomon the Wise wrote, “All that G‑d causes is for His sake, even the wicked on the day of his evil.” He brings a person to the door of sin and allows it to overpower the soul, so that the passion of sin will be transformed to the light of day.

But you need something more. Right now, you need the consequences of the past to change. And that is also possible.

You see, as long as that ugly deed remained unredeemed, it had its repercussions. The world is designed with justice; as one good deed begets another, so ugliness begets more of its own. But now that a destructive deed has been healed, whatever debris lay strewn in its path has been orphaned. It has no reason to have ever existed. Yes, there is a record. But G‑d can always find a way to re-orchestrate the past He has written.

There are stories of this. When I have the time, I can write you a few. Consequences of foolish acts that plagued their originator for years suddenly became benign; bad fortune astonishingly turned out to be success. All after a turn of heart and an opening up of the soul.

Perhaps I won’t have to write you any. Perhaps you will be the one to write to me your own.

For a thorough discussion on the topic of the effect of teshuvah upon the past, see Likkutei Sichot, vol. 17, Acharei 2.