1) HASH-M FORGIVES A PERSON'S FIRST SIN
QUESTION: A Tana in the school of Rebbi Yishmael taught that Hash-m is "Ma'avir Rishon Rishon" -- He passes over the first sin a person commits and does not hold the person accountable for it. Rava adds that if a person ends up with more Aveiros than Mitzvos, Hash-m counts every sin, including the one that He originally passed over.
The Gemara here seems to contradict the Gemara in Yoma (86b). The Gemara there says that Hash-m gives a person three chances. Hash-m forgives the first three sins which a person transgresses, but He does not forgive the fourth sin. The Gemara here says that only the first sin is forgiven. How are the two statements to be reconciled?
(a) The RAMBAM (Hilchos Teshuvah 3:5) writes that the Gemara in Yoma means that when Hash-m wants to determine whether the person has mostly Aveiros or mostly Mitzvos in the first place, He ignores the first few sins. After those sins are discarded, if there remains a majority of sins the person is punished for all of them, including the first ones. If, however, without the first few sins the person has a majority of Mitzvos, then Hash-m continues with the attribute described in the Gemara here and erases "Rishon Rishon," He expunges every remaining sin, one by one. Once the first sin has been expunged, the next one becomes the first and is also expunged, until all of the sins have been removed. (See also the words of the VILNA GA'ON in his commentary to Esther 2:12, who adds an original insight to this understanding.)
(b) The RITVA understands, from the words of the RIF and RABEINU CHANANEL, that both Gemaros are saying the same thing. When the Gemara here says that Hash-m is "Ma'avir Rishon Rishon," it means that when Hash-m erases the first sin, the second sin becomes the first and thus He erases it as well, and then the third becomes the first and He erases it, but He stops there and does not erase any more sins. He erases the first three sins and no more, just as the Gemara in Yoma says. (The RAN, however, asserts that the Rambam interpreted the words of the Rif to be expressing his understanding of the Gemara, in (a) above.)
The Rif and Rabeinu Chananel add that Hash-m applies this attribute only to a person who is an upright, virtuous person who has never before sinned. When such a person sins, Hash-m forgives his first three sins.
(c) The RITVA cites another explanation. The attribute of "Ma'avir Rishon Rishon" refers to the fourth sin. The first three sins are completely erased and are not recalled even if one ends up with a majority of sins. This is the subject of the Gemara in Yoma. The fourth sin, however, is erased through Hash-m's kindness, but if one ends up with a majority of sins, the fourth sin is counted along with them.
(d) The RA'AVAD (Hilchos Teshuvah 3:5) explains that the Gemara here discusses the yearly judgment in which Hash-m weighs all of a person's Mitzvos against his Aveiros. The Gemara in Yoma, in contrast, discusses a person who has not sinned at all from the time he became obligated to observe the Mitzvos (such as a minor who just reached the age of Bar Mitzvah). Since he is not yet accustomed to fighting his Yetzer ha'Ra, Hash-m forgives his first three sins and treats them with less strictness, even if the sins are very severe and would normally require afflictions and Yom Kippur to exculpate. Hash-m forgives them without afflictions and Yom Kippur, provided that the person does Teshuvah, because they were the first three sins that he did.
(The RITVA gives a similar explanation, but he maintains that Hash-m entirely forgives the first three sins and never takes them into account because a person so young is not yet fully responsible for his actions even though he has reached the age of Bar Mitzvah.)
2) HOW HASH-M TREATS A PERSON BEFORE HE SINS
QUESTION: The Gemara relates that whenever the Jewish people perform the declaration of the Thirteen Attributes of Hash-m's Mercy as listed in the Torah (Shemos 34:6-7), Hash-m forgives all of their sins. The Gemara quotes the first phrase in the verse, "Hash-m Hash-m," and explains that it means that "I am Hash-m before a person sins, and I am Hash-m after a person sins and repents." RASHI explains that this means that Hash-m acts with mercy, Rachamim, with a person before he sins.
Why does a person need Rachamim if he has not yet sinned?
(a) The ROSH says that Hash-m knows what a person will do in the future, but He punishes the person only after he has actually sinned. Hash-m has mercy on the person and lets him go unpunished until he actually commits the transgression. Hash-m judges a person only "ba'Asher Hu Sham" (see Bereishis 21:7).
(b) The ROSH, in his second answer, refers to the Gemara in Kidushin (39b) which states that if a person thinks about transgressing, Hash-m in His mercy does not consider his thought a sin. However, if a person thinks about committing the sin of Avodah Zarah, Hash-m considers the person's thought to be like an action, and he is held accountable as if he had actually sinned.
The Rosh explains that this attribute of Hash-m's Rachamim ("I am Hash-m before a person sins") applies to a person who sins with Avodah Zarah through thought. Only after the person does the act does Hash-m join the thought of idolatry to the act of idolatry, and He punishes the person for both. Until the person commits the act itself, though, Hash-m has mercy on the person and does not punish him for the thought of doing the act of idolatry.
(c) Other Rishonim (see Chart) do not count the two words "Hash-m Hash-m" as two separate attributes but rather as a single attribute of mercy. Accordingly, when the Gemara says, "I am Hash-m before a person sins," it does not mean (as Rashi explains) that Hash-m has Rachamim on a person before he sins. Rather, it means that Hash-m lovingly accepts a person even after he sins to the same degree that He accepted him when he was free of sin.