What happens to somebody who really says to himself, “I will sin then repent, sin then repent,” then does exactly so numerous times, however, later on realizes that this was his biggest mistake in life without a doubt, feels true genuine regret, begins to live an honest and upright life, is humble to himself and the people around him or her, changes his wicked ways once and for all, tries to repent with full love for Hashem, tries to do teshuvah in all honesty as effectively as possible with full heart, soul and intention, doesn’t want to lose the ability to do teshuvah, feels remorse and never returns to the sin again.
Does Hashem have mercy on such a Soul ?
Hashem has mercy on everyone’s soul. Everyone can do teshuva, even a person who says that he will sin and do teshuva afterwards. The Rambam says this clearly in the last halacha of the chapter that discusses those who will have a hard time correcting their sins. This is however on the condition that the person actually does teshuva sincerely, which is hard to do after saying that one will sin and do teshuva afterwards. This is because it is easy for the person to say, I’ll just sin again but I’ll do teshuva for it again. However, if the person is indeed sincere about the teshuva, it will be accepted.
It is important to note that there are three parts to Teshuva: regretting what was done wrong, confessing the sin to Hashem, and the most important part is a sincere commitment never to do this sin again. It is also brought that Hashem knows what is in the deep recesses of a person’s heart, and the commitment has to be strong enough that Hashem Himself is convinced of it. This can be very difficult. R’ Yisroel Salanter makes an important point regarding this. That even if a person cannot do teshuva for the whole sin, however it is still possible to do teshuva for part of the sin. For example, a person who sinned by doing or looking at inappropriate things. While he might not be able to make a rock-solid commitment not to look at anything inappropriate again, he can still make a clear commitment, not to use an unfiltered phone or unfiltered internet. By getting a filter on one’s phone etc., the person has done a complete teshuva, on at least part of the sin. After that the person will grow, and will be able to do a correct teshuva for the next level… The main point being that whatever the person accepts to do, that it will be easy enough for the person to actually carry it out, to the degree that the person will not say, “I’ll try…”, rather I will, (because what I am accepting upon myself is easy enough for me to really keep). Then (if the person is sincere about it) Hashem will accept his teshuva.
רמב”ם הלכות תשובה פרק ד הלכה א “ארבעה ועשרים דברים מעכבין את התשובה, ארבעה מהן עון גדול והעושה אחד מהן אין הקדוש ברוך הוא מספיק בידו לעשות תשובה לפי גודל חטאו. ואלו הן… (ד) והאומר אחטא ואשוב ובכלל זה האומר אחטא ויום הכפורים מכפר. וע”ש הלכה ו “כל אלו הדברים וכיוצא בהן אף על פי שמעכבין את התשובה אין מונעין אותה אלא אם עשה אדם תשובה מהן הרי זה בעל תשובה ויש לו חלק לעולם הבא”