Can I Sin Today and Repent Tomorrow?

A lot of the way we relate to Teshuva is learned from the following Pasuk. Avraham sent away Yishmael and Hagar and Yishmael was on the brink of death from dehydration. Hagar and Yishmael davened for his life and the Pasuk says that G-d judged Yishmael "where he is" i.e. as he was at that exact moment. There was no regard for the fact that he was a bad person in the past and may be bad in the future. At that very moment- Yishmael was worthy of being saved because of his Tefila and Teshuva.

(יז) וַיִּשְׁמַ֣ע אֱלֹהִים֮ אֶת־ק֣וֹל הַנַּעַר֒ וַיִּקְרָא֩ מַלְאַ֨ךְ אֱלֹהִ֤ים ׀ אֶל־הָגָר֙ מִן־הַשָּׁמַ֔יִם וַיֹּ֥אמֶר לָ֖הּ מַה־לָּ֣ךְ הָגָ֑ר אַל־תִּ֣ירְאִ֔י כִּֽי־שָׁמַ֧ע אֱלֹהִ֛ים אֶל־ק֥וֹל הַנַּ֖עַר בַּאֲשֶׁ֥ר הוּא־שָֽׁם׃

(17) God heard the cry of the boy, and an angel of God called to Hagar from heaven and said to her, “What troubles you, Hagar? Fear not, for God has heeded the cry of the boy where he is.

The only instance where people are not judged "as they are" is in the case of a Ben Sorer U'Moreh- A rebeliious son. The Mishna teaches that in this specific case (which never happened and never will happen) this person is so far gone- that Teshuva is impossible and they are judged based on what they will inevitably do in the future.

(ה) בֵּן סוֹרֵר וּמוֹרֶה נִדּוֹן עַל שֵׁם סוֹפוֹ, יָמוּת זַכַּאי וְאַל יָמוּת חַיָּב, שֶׁמִּיתָתָן שֶׁל רְשָׁעִים הֲנָאָה לָהֶן וַהֲנָאָה לָעוֹלָם, וְלַצַּדִּיקִים, רַע לָהֶן וְרַע לָעוֹלָם. יַיִן וְשֵׁנָה לָרְשָׁעִים, הֲנָאָה לָהֶן וַהֲנָאָה לָעוֹלָם, וְלַצַּדִּיקִים, רַע לָהֶן וְרַע לָעוֹלָם. פִּזּוּר לָרְשָׁעִים, הֲנָאָה לָהֶן וַהֲנָאָה לָעוֹלָם, וְלַצַּדִּיקִים, רַע לָהֶן וְרַע לָעוֹלָם. כִּנּוּס לָרְשָׁעִים, רַע לָהֶן וְרַע לָעוֹלָם, וְלַצַּדִּיקִים, הֲנָאָה לָהֶן וַהֲנָאָה לָעוֹלָם. שֶׁקֶט לָרְשָׁעִים, רַע לָהֶן וְרַע לָעוֹלָם, וְלַצַּדִּיקִים, הֲנָאָה לָהֶן וַהֲנָאָה לָעוֹלָם:

(5) A “wayward and rebellious son” is judged on account of his outcome: let him die innocent and let him not die guilty. For the death of the wicked benefits themselves and the world; [and the death] of the righteous, injures themselves and the world d. Wine and sleep of the wicked benefit themselves and the world; of the righteous, injure themselves and the world The scattering of the wicked benefits themselves and the world; of the righteous, injures themselves and the world. The assembling of the wicked injures themselves and the world; of the righteous, benefits themselves and the world. The tranquillity of the wicked injures themselves and the world; of the righteous, benefits themselves and the world.

This Mishna seems to address the question we are debating. Note: Pay close attention to the wording of the Mishna. It may not be as clear as it seems.

(ט) הָאוֹמֵר, אֶחֱטָא וְאָשׁוּב, אֶחֱטָא וְאָשׁוּב, אֵין מַסְפִּיקִין בְּיָדוֹ לַעֲשׂוֹת תְּשׁוּבָה. אֶחֱטָא וְיוֹם הַכִּפּוּרִים מְכַפֵּר, אֵין יוֹם הַכִּפּוּרִים מְכַפֵּר. עֲבֵרוֹת שֶׁבֵּין אָדָם לַמָּקוֹם, יוֹם הַכִּפּוּרִים מְכַפֵּר. עֲבֵרוֹת שֶׁבֵּין אָדָם לַחֲבֵרוֹ, אֵין יוֹם הַכִּפּוּרִים מְכַפֵּר, עַד שֶׁיְּרַצֶּה אֶת חֲבֵרוֹ. אֶת זוֹ דָּרַשׁ רַבִּי אֶלְעָזָר בֶּן עֲזַרְיָה, מִכֹּל חַטֹּאתֵיכֶם לִפְנֵי יְיָ תִּטְהָרוּ (ויקרא טז), עֲבֵרוֹת שֶׁבֵּין אָדָם לַמָּקוֹם, יוֹם הַכִּפּוּרִים מְכַפֵּר. עֲבֵרוֹת שֶׁבֵּין אָדָם לַחֲבֵרוֹ, אֵין יוֹם הַכִּפּוּרִים מְכַפֵּר, עַד שֶׁיְּרַצֶּה אֶת חֲבֵרוֹ. אָמַר רַבִּי עֲקִיבָא, אַשְׁרֵיכֶם יִשְׂרָאֵל, לִפְנֵי מִי אַתֶּם מִטַּהֲרִין, וּמִי מְטַהֵר אֶתְכֶם, אֲבִיכֶם שֶׁבַּשָּׁמַיִם, שֶׁנֶּאֱמַר (יחזקאל לו), וְזָרַקְתִּי עֲלֵיכֶם מַיִם טְהוֹרִים וּטְהַרְתֶּם. וְאוֹמֵר (ירמיה יז), מִקְוֵה יִשְׂרָאֵל יְיָ, מַה מִּקְוֶה מְטַהֵר אֶת הַטְּמֵאִים, אַף הַקָּדוֹשׁ בָּרוּךְ הוּא מְטַהֵר אֶת יִשְׂרָאֵל:

(9) One who says: I shall sin and repent, sin and repent, will not have the opportunity to repent. [If one says]: I shall sin and Yom HaKippurim will atone for me, Yom HaKippurim does not effect atonement. For transgressions between man and God Yom HaKippurim effects atonement, but for transgressions between man and his fellow Yom HaKippurim does not effect atonement, until he has pacified his fellow. This was expounded by Rabbi Elazar b. Azariah: “From all your sins before the Lord you shall be clean” (Leviticus 16:30) for transgressions between man and God Yom HaKippurim effects atonement, but for transgressions between man and his fellow Yom HaKippurim does not effect atonement, until he has pacified his fellow.. Rabbi Akiva said: Happy are you, Israel! Who is it before whom you become pure? And who is it that purifies you? Your Father who is in heaven, as it is said: “And I will sprinkle clean water upon you and you shall be clean” (Ezekiel 36:25). And it further says: “O hope (mikveh) of Israel, O Lord” (Jeremiah 17:1--just as a mikveh purifies the unclean, so too does he Holy One, blessed be He, purify Israel.

The following are excerpts from the Rambam's Hilchot Teshuva which define what proper Teshuva is. The bolded sections are supposed to be focused on. Any of the moderators or teachers can help with material that is unclear.

כָּל מִצְוֹת שֶׁבַּתּוֹרָה בֵּין עֲשֵׂה בֵּין לֹא תַּעֲשֶׂה אִם עָבַר אָדָם עַל אַחַת מֵהֶן בֵּין בְּזָדוֹן בֵּין בִּשְׁגָגָה כְּשֶׁיַּעֲשֶׂה תְּשׁוּבָה וְיָשׁוּב מֵחֶטְאוֹ חַיָּב לְהִתְוַדּוֹת לִפְנֵי הָאֵל בָּרוּךְ הוּא שֶׁנֶּאֱמַר (במדבר ה ו) "אִישׁ אוֹ אִשָּׁה כִּי יַעֲשׂוּ" וְגוֹ' (במדבר ה ז) "וְהִתְוַדּוּ אֶת חַטָּאתָם אֲשֶׁר עָשׂוּ" זֶה וִדּוּי דְּבָרִים. וִדּוּי זֶה מִצְוַת עֲשֵׂה. כֵּיצַד מִתְוַדִּין. אוֹמֵר אָנָּא הַשֵּׁם חָטָאתִי עָוִיתִי פָּשַׁעְתִּי לְפָנֶיךָ וְעָשִׂיתִי כָּךְ וְכָךְ וַהֲרֵי נִחַמְתִּי וּבֹשְׁתִּי בְּמַעֲשַׂי וּלְעוֹלָם אֵינִי חוֹזֵר לְדָבָר זֶה. וְזֶהוּ עִקָּרוֹ שֶׁל וִדּוּי. וְכָל הַמַּרְבֶּה לְהִתְוַדּוֹת וּמַאֲרִיךְ בְּעִנְיָן זֶה הֲרֵי זֶה מְשֻׁבָּח. וְכֵן בַּעֲלֵי חַטָּאוֹת וַאֲשָׁמוֹת בְּעֵת שֶׁמְּבִיאִין קָרְבְּנוֹתֵיהֶן עַל שִׁגְגָתָן אוֹ עַל זְדוֹנָן אֵין מִתְכַּפֵּר לָהֶן בְּקָרְבָּנָם עַד שֶׁיַּעֲשׂוּ תְּשׁוּבָה וְיִתְוַדּוּ וִדּוּי דְּבָרִים שֶׁנֶּאֱמַר (ויקרא ה ה) "וְהִתְוַדָּה אֲשֶׁר חָטָא עָלֶיהָ". וְכֵן כָּל מְחֻיְּבֵי מִיתוֹת בֵּית דִּין וּמְחֻיְּבֵי מַלְקוֹת אֵין מִתְכַּפֵּר לָהֶן בְּמִיתָתָן אוֹ בִּלְקִיָּתָן עַד שֶׁיַּעֲשׂוּ תְּשׁוּבָה וְיִתְוַדּוּ. וְכֵן הַחוֹבֵל בַּחֲבֵרוֹ וְהַמַּזִּיק מָמוֹנוֹ אַף עַל פִּי שֶׁשִּׁלֵּם לוֹ מַה שֶּׁהוּא חַיָּב לוֹ אֵינוֹ מִתְכַּפֵּר עַד שֶׁיִּתְוַדֶּה וְיָשׁוּב מִלַּעֲשׂוֹת כָּזֶה לְעוֹלָם שֶׁנֶּאֱמַר (במדבר ה ו) "מִכָּל חַטֹּאת הָאָדָם":

All commandments of the Torah, whether they be mandatory or prohibitive, if a man violates any one of them, either purposefully or accidentally, when he will repent himself and turn away from his sinful way, he is obliged to confess before God, blessed is He! even as it is said: "When a man or woman shall commit any sin..… Then they shall confess their sin which they have done (Num. 5.6–7), which is a confession of words. Such confession is a mandatory commandment. How is the verbal confession made? The sinner says thus: "I beseech Thee, O Great Name! I have sinned; I have been obstinate; I have committed profanity against Thee, particularly in doing thus and such. Now, behold! I have repented and am ashamed of my actions; forever will I not relapse into this thing again." This is the elementary form of confession; but whosoever elaborates in confessing and extends this subject is, indeed, praise-worthy. Likewise all those who bring sin-offerings or trespass-offerings, when they offer their sacrifices, whether for their errors or for their spitefulness, find no atonement in their sacrifices, unless they repent, and deliver themselves of a verbal confession, even as it is said: "He shall confess that he hath sinned in that thing" (Lev. 5.5) So, too, are the guilty upon whom the tribunal pronounced either a sentence of death or of stripes, who find no atonement either in their death or in being lashed unless they do repent and make verbal confession. Even he, who injures his friend or causes him damages in money matters, although he makes restitution of what he owes him, finds no atonement, unless he makes verbal confession and repents by obligating himself never to repeat this again, even as is said: "Any sin that man commits" (Num. 5.6).1Sifra, Lev. 5; Yoma, 36b; Shebu’ot, 13a; Sanhedrin, 43a; Baba Kama, 92b.C.

אֵי זוֹ הִיא תְּשׁוּבָה גְּמוּרָה. זֶה שֶׁבָּא לְיָדוֹ דָּבָר שֶׁעָבַר בּוֹ וְאֶפְשָׁר בְּיָדוֹ לַעֲשׂוֹתוֹ וּפֵרַשׁ וְלֹא עָשָׂה מִפְּנֵי הַתְּשׁוּבָה. לֹא מִיִּרְאָה וְלֹא מִכִּשְׁלוֹן כֹּחַ... אֲפִלּוּ עָבַר כָּל יָמָיו וְעָשָׂה תְּשׁוּבָה בְּיוֹם מִיתָתוֹ וּמֵת בִּתְשׁוּבָתוֹ כָּל עֲוֹנוֹתָיו נִמְחָלִין...

What is complete repentance? He who once more had in it in his power to repeat a violation, but separated himself therefrom, and did not do it because of repentance, not out of fear or lack of strength... Even if he made no reparation save in his old age, at a time when it was already impossible for him to repeat his misdeeds, although it is not the best repentance, it still is of help to him and he is considered a penitent. Moreover, though he continued a life of sin but did repent on his dying day, and did die a penitent, all of his sins are forgiven, even as it is said...

וּמַה הִיא הַתְּשׁוּבָה. הוּא שֶׁיַּעֲזֹב הַחוֹטֵא חֶטְאוֹ וִיסִירוֹ מִמַּחֲשַׁבְתּוֹ וְיִגְמֹר בְּלִבּוֹ שֶׁלֹּא יַעֲשֵׂהוּ עוֹד... וְצָרִיךְ לְהִתְוַדּוֹת בִּשְׂפָתָיו וְלוֹמַר עִנְיָנוֹת אֵלּוּ שֶׁגָּמַר בְּלִבּוֹ:

What is repentance? The sinner shall cease sinning, and remove sin from his thoughts, and wholeheartedly conclude not to revert back to it... It is, moreover, essential that his confession shall be by spoken words of his lips, and all that which he concluded in his heart shall be formed in speech.

אַרְבָעָה וְעֶשְׂרִים דְּבָרִים מְעַכְּבִין אֶת הַתְּשׁוּבָה. אַרְבָּעָה מֵהֶן עָוֹן גָּדוֹל וְהָעוֹשֶׂה אֶחָד מֵהֶן אֵין הַקָּדוֹשׁ בָּרוּךְ הוּא מַסְפִּיק בְּיָדוֹ לַעֲשׂוֹת תְּשׁוּבָה לְפִי גֹּדֶל חֶטְאוֹ. וְאֵלּוּ הֵן. א) הַמַּחְטִיא אֶת הָרַבִּים וּבִכְלַל עָוֹן זֶה הַמְעַכֵּב אֶת הָרַבִּים מִלַּעֲשׂוֹת מִצְוָה. ב) וְהַמַּטֶּה אֶת חֲבֵרוֹ מִדֶּרֶךְ טוֹבָה לְרָעָה כְּגוֹן מֵסִית וּמַדִּיחַ. ג) הָרוֹאֶה בְּנוֹ יוֹצֵא לְתַרְבּוּת רָעָה וְאֵינוֹ מְמַחֶה בְּיָדוֹ. הוֹאִיל וּבְנוֹ בִּרְשׁוּתוֹ אִלּוּ מִחָה בּוֹ הָיָה פּוֹרֵשׁ וְנִמְצָא כְּמַחְטִיאוֹ. וּבִכְלַל עָוֹן זֶה כָּל שֶׁאֶפְשָׁר בְּיָדוֹ לִמְחוֹת בַּאֲחֵרִים בֵּין יָחִיד בֵּין רַבִּים וְלֹא מִחָה אֶלָּא יַנִּיחֵם בְּכִשְׁלוֹנָם. ד) וְהָאוֹמֵר אֶחְטָא וְאָשׁוּב וּבִכְלַל זֶה הָאוֹמֵר אֶחְטָא וְיוֹם הַכִּפּוּרִים מְכַפֵּר:

Twenty-four different transgressions withhold the acceptance of repentance, four of these are of great iniquity, and whosoever commits one of them, the Holy One, blessed is He! provides no means for him to repent, measured, of course, with the monstrosity of his sin. They are: (1) he who leads the public to sin, by which is also included one who witholds the public from performing a commandment; (2) he who diverts his neighbor from the good path to an evil one, for instance, a seducer and an enticer; (3) he who beholds his son cultivating bad habits and does not protest against it, for, his son being under his control, probably, by having protested, he could have separated him therefrom, as a consequence whereof it is as if he himself led him to sin; by which is also included the iniquity of every one who has a possibility to protest against others, whether individuals or many, and does not protest against them but leaves them to their stumbling; (4) he who says: "I will sin and repent"; by which is also included one who says: "I will sin and the Day of Atonement will atone".

וְאַל יְדַמֶּה אָדָם בַּעַל תְּשׁוּבָה שֶׁהוּא מְרֻחָק מִמַּעֲלַת הַצַּדִּיקִים מִפְּנֵי הָעֲוֹנוֹת וְהַחֲטָאוֹת שֶׁעָשָׂה. אֵין הַדָּבָר כֵּן אֶלָּא אָהוּב וְנֶחְמָד הוּא לִפְנֵי הַבּוֹרֵא כְּאִלּוּ לֹא חָטָא מֵעוֹלָם. וְלֹא עוֹד אֶלָּא שֶׁשְּׂכָרוֹ הַרְבֵּה שֶׁהֲרֵי טָעַם טַעַם הַחֵטְא וּפֵרַשׁ מִמֶּנּוּ וְכָבַשׁ יִצְרוֹ. אָמְרוּ חֲכָמִים מָקוֹם שֶׁבַּעֲלֵי תְּשׁוּבָה עוֹמְדִין אֵין צַדִּיקִים גְּמוּרִין יְכוֹלִין לַעֲמֹד בּוֹ. כְּלוֹמַר מַעֲלָתָן גְּדוֹלָה מִמַּעֲלַת אֵלּוּ שֶׁלֹּא חָטְאוּ מֵעוֹלָם מִפְּנֵי שֶׁהֵן כּוֹבְשִׁים יִצְרָם יוֹתֵר מֵהֶם:

Let not a man who did Teshuva imagine that he is removed at a distance from the degree of the righteous on account of the iniquities and sins which he had committed. It is not so, but the Creator considers him beloved and desirable, as if he had ever known of no sin. Moreover, his reward is great; for, after having partaken of the taste of sin, he separated himself therefrom and conquered his passion. The sages said: "The place whereon the penitent stand the wholly righteous could not stand;" as if saying: "their degree is above the degree of those who ever did not sin, because it is more difficult for them to subdue their passion than for the others.