Rabbi Yosi said, Woe to the people of Esau, when that goat (one of the goat pair sacrificed on Yom Kippur) is sent to that slanderer (thrown over a steep craggy cliff called Azazel as a sacrifice to the Other Side, the spiritual ruler of Esau). He (the spiritual ruler of Esau) now comes to praise Israel [as a result of having received the bribe of goat thrown off the cliff as his portion]. G‑d returns all those iniquities [He accused Israel of] on the head of his people [to Edom, since He has now excused Israel from judgment but the sins still require expiation, and the accusation had come from the side of the kelipot]. This because of the verse, "he (the spiritual ruler of Esau) that tells lies shall not remain in my sight" (Ps. 101:7) [for even now he doesn’t seek to exonerate Israel as a result of the truth but only as a result of the bribe that he has taken]. Rabbi Yehuda said, If the idolaters knew of the goat [sent to Azazel], they would not let Israel live one day in the world.
The prosecutor turns into a defender and goes on his way.
Come and see all that day
[Yom Kippur] he (the spiritual ruler of Esau) busies himself (dividing the spoils of the leftovers of holiness bestowed) with that goat (from Above, and there is no accuser against Israel). Then G‑d forgives Israel and cleanses them in every aspect, and there is no prosecutor in His presence. He then comes and praises Israel. Then He asks him, as written, "And G‑d said to the adversary, From where do you come?" and he (the spiritual ruler of Esau) answers by praising Israel. The prosecutor turns into a defender and goes on his way.

G‑d then says to the seventy ministers that surround the throne
[the 70 members of the Heavenly Court that surrounds His throne], 'Have you seen this slanderer, how he is always ready to accuse and inform on My children? Look, there is one goat that was sent to him, with a note with all their iniquities, all their abominable acts and all that they sinned and transgressed before Me, and he accepted them upon himself. Then they unanimously agree that these iniquities go back on his people [Edom].

Rabbi Aba said, all the iniquities and sins are attached to him, as written, "And You will cast all their sins into the depths of the sea." (Micah 7:19)
[The depths of the sea are the Samech Mem and his female consorts.] Then all these iniquities return upon the heads of his people, as written, "and the goat shall bear upon it all their iniquities to a barren land" [the dwelling place of Sam-Kel and his female consorts]. (Lev. 16:22)

BeRahamim LeHayyim:
If repentance is done completely, then all of our sins are bagged up, as it were, and either buried ceremoniously at sea, or sent to a barren land in the desert. Gone. And we are "wiped clean," LeKaper, the proverbial tabula rasa/clean slate. It's like we are new people, who have rewritten the past. We are wiped clean, surely, but note, these sins are submerged with sort-of "cement shoes" in the deepest of depths. Too they are pushed off a cliff of sorts, and remain torn asunder at the bottom of a rocky valley.
...we are new people, who have rewritten the past.
They can be recovered! They can be brought back again if we fall into our old habits and miss-takes! They are gone, but not forgotten! Azazel is the initial letters of "This is opposite to This" — by our offering up of our blemishes, this spiritual force is satisfied, and we are no longer accused above.

Our motivation to remain in this good place should not come from the lower level fear of punishment, but rather from the higher level awe of not wanting to upset the amazing relationship we have with the King, to whom we are now in His good graces. Sort of like when your father forgives you for a miss-take you did as a kid: most of us did not repeat the delinquency the next time!