If a person returns to Islam after leaving it, he should continue to give the rights to those whom he has oppressed them or taken it from them.

The sins that were done before nullifying Islam must be repented from and they wouldn’t be forgiven by returning to Islam.

This happens only with the original disbeliever who reverts to Islam for the first time.

I commited major kufr in the past but I have repented now and I came back into Islam again but I have a question, in the past I slandered some people them and I never asked them for forgiveness. I know when someone comes back into Islam all of their past sins are forgiven but what about this sin, have i been forgiven for it when i entered Islam again or will i be forgiven only when i ask them for forgiveness?