In the fourth chapter of his Hilchot Teshuva, the Rambam (Rabbi Moshe Maimonides, Spain-Egypt, 1135-1204) lists twenty-four factors that could interfere with the process of Teshuva by making it difficult for a person to repent and earn forgiveness. The first four, he writes, involve particularly grievous sins on account of which God withholds the assistance He normally affords those who seek to repent:
1) "Mahati Et Ha'rabim" causing the public to sin. This includes situations such as hosting a large event where non-kosher food is served, or disrupting people attempting to perform a Misva.
2) Persuading another person to leave the path of Torah observance, such as through missionary work.
3) Neglecting to reprimand one's child who begins leaving the path of Torah observance. If the parent has the ability to exert influence over the child and thereby prevent his departure from Jewish practice, yet he fails to do so, then this could prevent him from proper performance of Teshuva. The Rambam adds that this includes any case of a person who is in a position to positively influence others yet fails to do so.
4) "Ha'omer Eheta Ve'ashuv" committing a transgression with the initial intent of later performing Teshuva. If a person sins relying on the atonement he could achieve through repentance, or through the observance of Yom Kippur, then this sin might interfere with his process of Teshuva.
It must be emphasized that the Rambam does not preclude the possibility of such sinners performing Teshuva and earning forgiveness; ever under such circumstances the possibility of repentance remains. Rather, he speaks here of the special assistance and support that God grants sinners when they sincerely commit themselves to repent. In these cases, the individual will be denied this unique assistance and may thus encounter considerable difficulty in performing Teshuva and earning God's acceptance.
