Forgiveness has limitations in African Religion. That is, there are evils which can be forgiven and others which cannot be forgiven. Furthermore, there are sins which are regarded as for individual that require individual forgiveness and others regarded as sins against the community and required being cleansed or forgiven by the community.
For example, one of the evils that cannot be forgiven is that of a man turning round and raping his mother or sister. Or a father turning round and raping his daughter. Such acts of evil deserve an immediate curse. A curse is a declaration of disowning the sinner and appealing to spirits and God to punish him.
When Catholic missionaries arrived in Africa carrying the Bible with the promise that no sin whatsoever that cannot be forgiven, and that if you had sinned all that you required in order for your innocence to be restored was to go to church on Sunday and confess to Catholic Priest your sin. The priest posed as the mediator between you and your God. So, after listening to your confession the Priest would then pray before you and ask God to forgive you. That having been accomplished you thereafter walked out of the church as a cleansed person.
That revelation was the most appealing news to people prone to mischief. It was good news because African Religion is rigid about forgiveness. If you sin and decided to seek forgiveness, that forgiveness was not as simple as it was in church. It subjected you to rigid rituals some of which may be very expensive. That was why in the search of God-of-easy-forgiveness many people abandoned African Religion and got converted into Christianity. That was how the storm of immorality gained deep roots in Africa.