Rashi
In the beginning: Said Rabbi Isaac: It was not necessary to begin the Torah except from “This month is to you,” (Exod. 12:2) which is the first commandment that the Israelites were commanded. Now for what reason did He commence with “In the beginning?” Because of [the verse] “The strength of His works He related to His people, to give them the inheritance of the nations” (Ps. 111:6). For when the nations of the world should say to Israel, “You are robbers, for you conquered by force the lands of the seven nations [of Canaan],” they will reply, "The entire earth belongs to the Holy One, blessed be He; He created it (this we learn from the story of the Creation) and gave it to whomever He deemed proper When He wished, He gave it to them, and when He wished, He took it away from them and gave it to us.
Rambam, Laws of Teshuva, 7:3
A Baal-Teshuvah should not consider himself distant from the level of the righteous because of the sins and transgressions that he committed. This is not true. He is beloved and desirable before the Creator as if he never sinned.Furthermore, he has a great reward for he has tasted sin and yet, separated himself from it, conquering his [evil] inclination. Our Sages declared: "In the place where Baalei Teshuvah stand, even the completely righteous are not able to stand." The level of Baalei Teshuvah transcends the level of those who never sinned at all, for they overcome their [evil] inclination more.