Do the sins from which a person has repented and to which he has not returned cause: lack of success in marriage, inability to deal with others, forgetfulness and mental wandering and poor retention, others disliking the sinner, and the occurrence of afflictions such as car accidents?

Sins and transgressions are among the greatest causes of calamities and hardships, as Allah says: "And whatever strikes you of disaster - it is because of what your hands have earned, and He pardons much." (Quran 42:30). Indeed, sustenance may be withheld due to sins. However, calamities may also be a test for a person or a means to elevate their status. Whoever repents with sincere repentance, Allah accepts their repentance and pardons them, as Allah says: "And He is the One who accepts repentance from His servants and pardons sins." (Quran 42:25). The one who repents from a sin is like one who has no sin. Whoever regularly seeks forgiveness, Allah will grant them relief and sustenance from where they do not expect. It is not possible to definitively state that a specific calamity is caused by a specific sin, as that is part of the unseen.