Is the repentance of one who mocked God accepted if he was disobedient to his parents, and is he sinful if he gradually improves the relationship?

Mocking Allah and disobeying parents are among the major sins. However, Allah Almighty accepts the sincere repentance of a servant as long as it occurs before the death rattle or the sun rising from the west, for one who repents from a sin is like one who has no sin. Initiating repentance is an immediate obligation, and delaying it is forbidden. Procrastination by saying, "Until Allah guides me," is not permissible. Rather, this person must promptly repent, honor their parents, and treat them with kindness.