Why Teshuvah Works.
Vayelech (Deuteronomy 31 )
“It shall be that when many evils and distresses come upon it, then this song shall speak up before it as a witness for it shall not be forgotten from the mouth of its offspring, for I know its inclination” (Deut. 31:21).
Malbim interprets this verse as a Divine promise to be forgiving when the Children of Israel will do teshuvah, repentance.
Malbim cites the Talmud which states that the prophet Elijah pleaded for the Israelites who had become idolatrous, saying to God, “It was You Who made it possible for them to go astray,” and that God admitted, “Yes, I created the yetzer hara, the evil inclination” (Berachos 32b). God accepts part of the responsibility for our sins, having created so powerful a yetzer hara.
Forgiveness requires teshuvah: regret for having sinned and a sincere resolution not to repeat the sinful act. But why is teshuvah effective? If a person commits a crime and pleads before the judge, “I'm sorry I did it and I promise I will never do it again,” this will hardly stop the judge from imposing a penalty.
Teshuvah is effective because God understands how vulnerable we are to the cunning and temptations of the yetzer hara. Therefore, if we realize that we have been duped by the yetzer hara, God takes this into consideration.
The chassidic master, the Shpoler Zeide, used to plead for his people, “Master of the universe! You have placed temptations before people's eyes, but the punishments of Gehinnom (hell) are described in the books. If You had placed Gehinnom right before people's eyes and the temptations in the books, I assure You, no one would sin.”
There is no justification for sin, but if a person who has sinned does teshuvah, God assumes part of the responsibility and forgives the sin.
This, Malbim says, is the promise in the above verse. “It shall be that when many evils and distresses come upon it, then this song shall speak before it as a witness . . . for I know its inclination.” When the troubles that befall Israel will cause us to do teshuvah, God promises to forgive, because He knows the power of the evil inclination. This song, the Torah, “shall not be forgotten from the mouths of its offspring,” and it will be a witness to plead in our behalf.
A person may be discouraged from doing teshuvah, thinking, “What's the use? I cannot expect God to forgive me for having disobeyed Him for so long.” God promises that if a person does teshuvah, He will enter a plea in his behalf, assuming part of the responsibility for the person's behavior.
It is never too late for teshuvah.