At the end of Parshas Mishpatim, the Torah returns to the narrative of the Sinai Revelation. (The commentaries debate whether the events described in Exodus 24 took place before or after the revelation of the Aseres Hadibros (Ten Commandments) described in Parshas Yisro.) It is here we find the famous declaration of the Jewish people (Exodus 24:7), "All that God has spoke, we shall do and we shall hear."
Israel entered the covenant through three things: Circumcision, immersion [in a mikva], and korban (a sacrifice). The circumcision took place in Egypt, as it states (Exodus 12:48), "And no uncircumcised man eat of it (the Paschal lamb)." ... Immersion was performed in the wilderness before the Giving of the Torah, as it says (19:10), "Sanctify them today and tomorrow and they shall wash their clothing." And the korban, as it says, ""And he sent the youths of the children of Israel and they brought up elevation-offerings." They made these sacrifices on behalf of all Israel.
The Giving of the Torah at Mt. Sinai was what made the Jewish people Jewish; it was their conversion to Judaism, and it serves as the model for all later conversion. As Maimonides continues:
And so it is for [future] generations, when a non-Jew wishes to enter the covenant and shelter beneath the wings of the Shechina and he accepts upon himself the yoke of the Torah, he requires circumcision, immersion, and offering a korban. If she is a woman, she requires [only] immersion and a korban. For the Torah says (Numbers 15:15), "As for you, so for the convert," [meaning] just as you required circumcision, immersion, and the offering of a korban, a convert in [future] generations will also require circumcision, immersion, and the offering of a korban. ... And in our time, when we cannot bring korbanos, a convert requires circumcision and immersion, and when the Temple is built he will bring his korban.
This event was the highest pinnacle of spiritual achievement in the history of the Jewish people. The Talmud (Shabbos 88a) tell us that when the Jewish people declared, "We shall do and we shall hear", six hundred thousand angels came and set two crowns upon each Jewish man. Yet, just forty days later, the Jewish people sinned with the golden calf, and, the Talmud continues, they lost those crowns that they had earned only a short time before. Ultimately, despite the powerful and transformative experience of their conversion, the Jewish people were still subject to the same challenges and temptations that they had been subject to before they underwent their conversion.
If this was true even for the Jewish nation at Sinai, it is certainly true for converts of later generations. Despite the fact that conversion definitely effects a fundamental spiritual change in the spiritual makeup of the convert, the convert nevertheless retains the same basic personality, with the same spiritual challenges and difficulties that he had before his conversion. Indeed, earlier in this parsha (23:9), we are commanded, "Do not oppress a stranger (i.e. a convert); you know the nature of a stranger, for you were strangers in the land of Egypt." Rashi comments (based on Bava Metzia 59b):
בהרבה מקומות הזהירה תורה על הגר, מפני שסורו רע
The Torah admonishes in many places regarding [afflicting] the convert, because his original nature is bad (and he is therefore more likely to abandon the Torah - Gur Aryeh).
As should be self-evident, this does not mean that converts are inherently "bad" people. There are innumerable sources that speak of the great virtues of converts (including the medrash upon which I based the name of this blog). The point is that, just as that first generation of Jews faced exceptional challenges because of their background in Egypt, a convert also faces spiritual challenges that are far more difficult that those faced by someone who was born a Jew, and we are required to bear this in mind when we interact with a convert. It is also of vital importance for those who mentor converts to be sure to make this clear to a potential convert. It is all too easy for a potential convert to imagine that his conversion will transform him into a new reborn being, without the challenges and difficulties that he had before conversion. This is simply a falsehood, and only sets the convert up for a sense of failure and rejection when it inevitably fails to come true.
The truth is that this principle is relevant not just for converts, but for every Jew. We all face spiritual challenges with which we struggle and we are taught that God helps us in our struggles with the yetzer hara (evil inclination), as in the famous Talmudic passage (Yoma 38b), "בא לטהר מסייעין אותו" - "one who comes to be purified, they (i.e. Heavenly forces) help him." We are even supposed to pray to God for such help, and we find such prayers in the traditional prayer services. People sometimes misunderstand these teachings to mean that if they just try hard enough, at some point God will simply take their yetzer hara away from them. The reality, however, is that God does not - ever - directly change us for the better. As Maimonides states in Moreh Nevuchim (III:32):
The nature of man is never changed by God by way of miracle.... it has never never been His will to do it and it never will be. If it were part of His will to change the nature of any person, the mission of the prophets and the giving of the Law would have been altogether superfluous.
The sources that describe God's help in our struggles with temptation are telling us only that if a person has truly reached the limits of his ability - so that he literally no longer has the ability to resist succumbing to sin - then God will give him the strength to continue the struggle. God helps us with our struggle, by giving us the strength to keep fighting, but the struggle itself is ultimately entirely our responsibility and it will end only when we pass on to the next world. (See my previous discussion of this concept: Va'eira - The Hardening of Pharaoh's Heart.)
The Baal Shem Tov ('ספר הבעש"ט לך לך ג) is quoted as saying in the name R' Saadia Gaon, כי עיקר בריאת האדם בעוה"ז הוא לשבר מדות רעות שלו הטבעיות - "The primary purpose for the creation of man in this world is for him to break his natural bad characteristics." The struggle to overcome our natural, inborn urges is the primary purpose of our existence. It is the reason why we are here in this world.