How did God forgive the man who killed 99 people and admit him to Paradise, even though the rights of people are not waived by repentance, and how will God forgive them on the Day of Resurrection, even though he did not restore their rights to them?

Sins are of two types: 1. Those that pertain to the right of Allah Almighty (such as alcohol and fornication). The one who commits these is subject to the will of Allah, and whoever repents from them, Allah accepts their repentance. 2. Those that involve both the right of Allah and the right of His servants (such as murder and theft). The rights of servants are not forfeited by repentance; rather, they must be fulfilled or their owners must be appeased.

Some scholars have interpreted the hadith of the murderer of a hundred souls to mean that Allah Almighty will appease the adversaries of a sincere penitent. If Allah accepts a servant's repentance, He will then appease their adversary or take responsibility for their appeasement. The rights of the wronged are not lost with Allah.