There is no question of the soul realizing anything and repenting. Yes, the best that we can think is that the ME – Mind and Ego, has to pay for its sins and repent or be rewarded for its good deeds, and that is not possible till the Mind and Ego (ME) takes another birth, because it has to have a physical manifestation before it can undergo any kind of repentance. The mind and ego, otherwise, only has a subtle existence, an existence which is non-physical and there can be no repentance in that state. It has to come back, return, in a state of physical being to experience any reward or repentance.
Different religions talk about different things, but one has to evolve and go beyond one’s religion and learn the spiritual truth to realize the truth behind this statement or question.