Acharei Mot and Acharayut (Responsibility) based on the Torah Mussar Commentary
(א) וַיְדַבֵּ֤ר יְהֹוָה֙ אֶל־מֹשֶׁ֔ה אַחֲרֵ֣י מ֔וֹת שְׁנֵ֖י בְּנֵ֣י אַהֲרֹ֑ן בְּקׇרְבָתָ֥ם לִפְנֵי־יְהֹוָ֖ה וַיָּמֻֽתוּ׃
(1) יהוה spoke to Moses after the death of the two sons of Aaron who died when they drew too close to the presence of יהוה.
(א) וַיִּקְח֣וּ בְנֵֽי־אַ֠הֲרֹ֠ן נָדָ֨ב וַאֲבִיה֜וּא אִ֣ישׁ מַחְתָּת֗וֹ וַיִּתְּנ֤וּ בָהֵן֙ אֵ֔שׁ וַיָּשִׂ֥ימוּ עָלֶ֖יהָ קְטֹ֑רֶת וַיַּקְרִ֜יבוּ לִפְנֵ֤י יְהֹוָה֙ אֵ֣שׁ זָרָ֔ה אֲשֶׁ֧ר לֹ֦א צִוָּ֖ה אֹתָֽם׃ (ב) וַתֵּ֥צֵא אֵ֛שׁ מִלִּפְנֵ֥י יְהֹוָ֖ה וַתֹּ֣אכַל אוֹתָ֑ם וַיָּמֻ֖תוּ לִפְנֵ֥י יְהֹוָֽה׃ (ג) וַיֹּ֨אמֶר מֹשֶׁ֜ה אֶֽל־אַהֲרֹ֗ן הוּא֩ אֲשֶׁר־דִּבֶּ֨ר יְהֹוָ֤ה ׀ לֵאמֹר֙ בִּקְרֹבַ֣י אֶקָּדֵ֔שׁ וְעַל־פְּנֵ֥י כׇל־הָעָ֖ם אֶכָּבֵ֑ד וַיִּדֹּ֖ם אַהֲרֹֽן׃
(1) Now Aaron’s sons Nadab and Abihu each took his fire pan, put fire in it, and laid incense on it; and they offered before יהוה alien fire, which had not been enjoined upon them. (2) And fire came forth from יהוה and consumed them; thus they died at the instance of יהוה. (3) Then Moses said to Aaron, “This is what יהוה meant by saying:
Through those near to Me I show Myself holy,
And gain glory before all the people.”And Aaron was silent.
Rabbi Peter Schaktman, "Acharayut—Responsibility: The Personal and the Communal" in Block, Rabbi Barry H.. The Mussar Torah Commentary: A Spiritual Path to Living a Meaningful and Ethical Life (pp. 179-180).
Hidden in the name of the parashah is a key to understanding the middah of acharayut (אַחֲרָיוּת, “responsibility”). The root of the first word, acharei (אַחֲרֵי, “after”), is the same as that of the middah, acharayut. Our Mussar teachers have taught us that this single root can be understood in two different ways, both of which help us discern the essence of the middah.1 When we connect acharayut to achar, to “after,” we understand responsibility as measuring the consequences of our actions or words. The Rabbinic tradition considers us “forewarned,” so that—as long as we possess free will—we are always responsible for the consequences of our words or actions, whether deliberate or inadvertent.2 When, on the other hand, we connect acharayut to acheir (אַחֵר, “other”), our focus is on our duties to those around us and our realization that we are, in fact, “our brother’s keeper” (Genesis 4:9).
Acharayut and Acharei/After

(ב) וַיֹּ֨אמֶר יְהֹוָ֜ה אֶל־מֹשֶׁ֗ה דַּבֵּר֮ אֶל־אַהֲרֹ֣ן אָחִ֒יךָ֒ וְאַל־יָבֹ֤א בְכׇל־עֵת֙ אֶל־הַקֹּ֔דֶשׁ מִבֵּ֖ית לַפָּרֹ֑כֶת אֶל־פְּנֵ֨י הַכַּפֹּ֜רֶת אֲשֶׁ֤ר עַל־הָאָרֹן֙ וְלֹ֣א יָמ֔וּת כִּ֚י בֶּֽעָנָ֔ן אֵרָאֶ֖ה עַל־הַכַּפֹּֽרֶת׃ (ג) בְּזֹ֛את יָבֹ֥א אַהֲרֹ֖ן אֶל־הַקֹּ֑דֶשׁ בְּפַ֧ר בֶּן־בָּקָ֛ר לְחַטָּ֖את וְאַ֥יִל לְעֹלָֽה׃

(2) יהוה said to Moses: Tell your brother Aaron that he is not to come at will into the Shrine behind the curtain, in front of the cover that is upon the ark, lest he die; for I appear in the cloud over the cover. (3) Thus only shall Aaron enter the Shrine: with a bull of the herd for a sin offering and a ram for a burnt offering.—
Rabbi Peter Schaktman
Here, the rationale for compliant behavior is the avoidance of dire consequences—acharayut in its sense of after-effects—in this case, death. Once Aaron understands the basic rules, he can begin the process of purgation of the sacred space. This process begins with the High Priest’s offering on behalf of himself and his household.

(יא) וְהִקְרִ֨יב אַהֲרֹ֜ן אֶת־פַּ֤ר הַֽחַטָּאת֙ אֲשֶׁר־ל֔וֹ וְכִפֶּ֥ר בַּֽעֲד֖וֹ וּבְעַ֣ד בֵּית֑וֹ וְשָׁחַ֛ט אֶת־פַּ֥ר הַֽחַטָּ֖את אֲשֶׁר־לֽוֹ... (טו) וְשָׁחַ֞ט אֶת־שְׂעִ֤יר הַֽחַטָּאת֙ אֲשֶׁ֣ר לָעָ֔ם וְהֵבִיא֙ אֶת־דָּמ֔וֹ אֶל־מִבֵּ֖ית לַפָּרֹ֑כֶת וְעָשָׂ֣ה אֶת־דָּמ֗וֹ כַּאֲשֶׁ֤ר עָשָׂה֙ לְדַ֣ם הַפָּ֔ר וְהִזָּ֥ה אֹת֛וֹ עַל־הַכַּפֹּ֖רֶת וְלִפְנֵ֥י הַכַּפֹּֽרֶת׃ (טז) וְכִפֶּ֣ר עַל־הַקֹּ֗דֶשׁ מִטֻּמְאֹת֙ בְּנֵ֣י יִשְׂרָאֵ֔ל וּמִפִּשְׁעֵיהֶ֖ם לְכׇל־חַטֹּאתָ֑ם וְכֵ֤ן יַעֲשֶׂה֙ לְאֹ֣הֶל מוֹעֵ֔ד הַשֹּׁכֵ֣ן אִתָּ֔ם בְּת֖וֹךְ טֻמְאֹתָֽם׃ (יז) וְכׇל־אָדָ֞ם לֹא־יִהְיֶ֣ה ׀ בְּאֹ֣הֶל מוֹעֵ֗ד בְּבֹא֛וֹ לְכַפֵּ֥ר בַּקֹּ֖דֶשׁ עַד־צֵאת֑וֹ וְכִפֶּ֤ר בַּעֲדוֹ֙ וּבְעַ֣ד בֵּית֔וֹ וּבְעַ֖ד כׇּל־קְהַ֥ל יִשְׂרָאֵֽל׃ (יח) וְיָצָ֗א אֶל־הַמִּזְבֵּ֛חַ אֲשֶׁ֥ר לִפְנֵֽי־יְהֹוָ֖ה וְכִפֶּ֣ר עָלָ֑יו ... (כ) וְכִלָּה֙ מִכַּפֵּ֣ר אֶת־הַקֹּ֔דֶשׁ וְאֶת־אֹ֥הֶל מוֹעֵ֖ד וְאֶת־הַמִּזְבֵּ֑חַ וְהִקְרִ֖יב אֶת־הַשָּׂעִ֥יר הֶחָֽי׃ (כא) וְסָמַ֨ךְ אַהֲרֹ֜ן אֶת־שְׁתֵּ֣י יָדָ֗ו עַ֣ל רֹ֣אשׁ הַשָּׂעִיר֮ הַחַי֒ וְהִתְוַדָּ֣ה עָלָ֗יו אֶת־כׇּל־עֲוֺנֹת֙ בְּנֵ֣י יִשְׂרָאֵ֔ל וְאֶת־כׇּל־פִּשְׁעֵיהֶ֖ם לְכׇל־חַטֹּאתָ֑ם וְנָתַ֤ן אֹתָם֙ עַל־רֹ֣אשׁ הַשָּׂעִ֔יר וְשִׁלַּ֛ח בְּיַד־אִ֥ישׁ עִתִּ֖י הַמִּדְבָּֽרָה׃ (כב) וְנָשָׂ֨א הַשָּׂעִ֥יר עָלָ֛יו אֶת־כׇּל־עֲוֺנֹתָ֖ם אֶל־אֶ֣רֶץ גְּזֵרָ֑ה וְשִׁלַּ֥ח אֶת־הַשָּׂעִ֖יר בַּמִּדְבָּֽר׃

(11) Aaron shall then offer his bull of sin offering, to make expiation for himself and his household. He shall slaughter his bull of sin offering... (15) He shall then slaughter the people’s goat of sin offering, bring its blood behind the curtain, and do with its blood as he has done with the blood of the bull: he shall sprinkle it over the cover and in front of the cover. (16) Thus he shall purge the Shrine of the impurity and transgression of the Israelites, whatever their sins; and he shall do the same for the Tent of Meeting, which abides with them in the midst of their impurity. (17) When he goes in to make expiation in the Shrine, nobody else shall be in the Tent of Meeting until he comes out. When he has made expiation for himself and his household, and for the whole congregation of Israel, (18) he shall go out to the altar that is before יהוה and purge it... (20) When he has finished purging the Shrine, the Tent of Meeting, and the altar, the live goat shall be brought forward. (21) Aaron shall lay both his hands upon the head of the live goat and confess over it all the iniquities and transgressions of the Israelites, whatever their sins, putting them on the head of the goat; and it shall be sent off to the wilderness through a designated agent. (22) Thus the goat shall carry on it all their iniquities to an inaccessible region; and the goat shall be set free in the wilderness.

Rabbi Peter Schaktman,
The azazel narrative also helps understand the potential for acharayut, like all middot, to be taken to an extreme, by calling to mind the important distinction between responsibility and guilt. While responsibility leads to greater wholeness, guilt—neurotic, and often narcissistic—instead engenders anxiety. Guilt is a source of spiritual negativity, a potentially debilitating state of being. No such angst is associated with the scapegoat. The ritual is prescribed, the High Priest and people enact it, and what results is a cleansed, confident community that has acted responsibly.
Alan Morinis, Everyday Holiness, p 198
finding the root of this soul-trait in the concept “after”—we are drawn toward recognizing that every single thought, word, or deed has its “after”—its antecedent and its consequence, connecting up in a great chain of cause and effect that spreads over time. We humans are unique among creatures in being able to anticipate consequences to the extent that we can, and as a result, we bear responsibility for our actions. “Who is wise?” asks Pirkei Avot, and Rabbi Shimon ben Netanel answers, “One who sees what is born [i.e., the outcome].”
And because we are able to foresee the future and we are wise to do so, the principle is established in the Mishnah that human beings are always responsible for the consequences of their actions, whether what occurred was the result of action that was voluntary or involuntary, deliberate or inadvertent. We’ll soon modify this all-encompassing view of our responsibility, but the message here is clear that each of us is called upon to take responsibility now for what we will cause to happen after.
ACHARAYUT and "Acheir/Other"
Rabbi Peter Schaktman,
Note that the word acharayut, begins, as does the Hebrew alphabet, with alef and ends with tav (the last letter of the alphabet), which may suggest that responsibility must be all-inclusive. We are accountable not only for our own actions but also for those of our families and the wider community.

שכל ישראל ערבים זה בזה

the entire Jewish people are considered guarantors for one another. Apparently, any transgression makes the entire world liable to be punished.

Rabbi Simcha Zissel Ziv, Chochmah u'Mussar
"Our sages taught: One of the methods by which the Torah is acquired is by carrying the burden of our fellow. "
Rabbi Simcha Zissel Ziv, as quoted in Everyday Holiness
This is the reason why our ancestors occupied themselves as shepherds like Jacob, peace be upon him, and David. Moses our teacher was also a shepherd because he wanted to accustom himself to bear the burden even of the simple creatures and all the more so of fellow human beings. . . . David would bring out the young sheep first to pasture in order that they could graze the best grass. Afterward, he would take out the old ones in order to give them ordinary grass. Finally, he would bring out the strong ones who could graze on the tough grass. . . . As our Rabbis said: “When Moses our teacher, peace be upon him, was the shepherd of Yitro, one of my lambs fled and Moses ran after it until it reached a watering hole where the lamb had stopped to drink. When Moses arrived he said: ‘I did not know that you fled on account of thirst. You must be tired.’ He lifted him on his shoulders and walked.”
Alan Morinis, Everyday Holiness (p.208)
When we think of responsibility as deriving from awareness of “after” (achar), contemplating and including in your calculations the possible consequences of your actions requires that you overcome the urge to satisfy your ego and your desires right now. In regard to the second derivation of achrayut—from acher, meaning “other”—to live a life in which you actively reach out to bear the burden of your neighbor requires that you quiet the demanding voice of desire and ego in order that you can hear the voice and feel the need of the other and respond. Though these roots may be different, they both connect up to the same stalk. The message is clear. We are capable of being responsible, and indeed we are inclined to be responsible. There is also undeniable benefit both practically and spiritually to being responsible. But we face a major obstacle to being responsible, which is our tendency to slavishly feed our selves in this moment. This is a force as strong as gravity for us to overcome. Responsibility, then, takes on even greater importance because it stands for and reflects a central thrust of spiritual growth, which is to rise up and beyond living in our small self who is interested only in gratification in the present, to evolve into the larger self who, from its elevated vantage point, can see and take in both the larger sweep of time and the living presence of others. Responsibility is both the means and the fruit of that evolution.