Are the previous sins of a person who becomes a Muslim forgiven?

- Are the previous sins of a person who is a non-Muslim (Christian, Jew, etc.) forgiven when he becomes a Muslim?
- Is there a definite rule like that in our religion?
- Or is it something that Allah knows?

Dear Brother / Sister,

All of the sins except violation of other people’s rights of a new Muslim are forgiven. Allah may forgive a slave that has become a Muslim about the violation of other people’s rights without harming the violated rights of the people.

Allah does not oppress anybody; He gives the rights of everybody. Individual rights may seem to be between two people but God Almighty will increase the sustenance of the person whose rights were violated, keep misfortunes away from him, etc. in the world and He will grant him things that will please him in the hereafter and elevate his rank; thus, He will not lose his rights and will make him pleased.

Questions on Islam