A person used to commit many sins, but now he has repented. Is he required to perform expiation for those sins?

Question:
I used to commit great sins, but I have now repented, praise be to Allah, and I cry a lot over what I did. Do I have to perform expiation for those sins, and will my Lord forgive me? I am distressed. May Allah reward you with good.

Answer:
Yes, repentance is obligatory for the Muslim regarding all sins. Allah, Glorified and Exalted is He, commanded repentance in many verses, and the Prophet (peace and blessings be upon him) commanded repentance in many authentic hadiths.
And His saying, the Exalted: as in His saying, the Exalted: and they give thanks to Him, and His saying, the Exalted: So repentance is obligatory from every sin, and Allah forgives all sins for whoever repents to Him with a valid repentance. And what the questioner mentioned, that he repented and felt remorse before Allah, and that he began to cry when he remembered his sins, this is a sign of good. And it is evidence for a condition of repentance, because one of the conditions of repentance is remorse for the sins and disobedience that have passed.
As for expiation, this varies depending on the sins. If the sin was killing a soul without right, or if the sin involved encroaching on someone’s person, wealth, or honor, then it is necessary to fulfill the rights to their owners. If the right is retaliation (qisas), then he must allow retaliation against himself or seek forgiveness. If the right is money, then he must pay it to the rightful owner or seek his forgiveness. If these sins involve the creation, harming them, or encroaching on them, then it is necessary to fulfill the rights to their owners and seek their forgiveness. However, if the sins are between the servant and his Lord, with no connection to the rights of the creation, then sincere repentance is sufficient for them, and Allah accepts the repentance of whoever He loves. May Allah reward you with good, and may He do you good.