I have noticed that AFIHMI is used predominantly in the Gospels and Acts for forgive/forgave, but Paul exclusively uses CARIZOMAI (except where he quotes the LXX in Ro4:7).
The spheres of meaning given in BDAG are:
AFIHMI – dismiss/release someone or something from a place, release from legal or moral obligations or consequence, move away/separate etc
CARIZOMAI – give freely as a favor, give graciously, cancel a sum of money that is owed, to show oneself gracious by forgiving wrongdoing etc
Obviously the words carry a slightly different sense of meaning even when being used in the context ‘to forgive’ – but I don’t understand why Paul would so consistently use CARIZOMAI in favour of AFIHMI, while the Gospel writers . In 1Jn there is the occasional use of AFIHMI so not all epistle writers preferred CARIZOMAI. In the Gospels CARIZOMAI is only used in Lk7 and then is carrying the meaning of cancelling of a finacial debt rather than forgiveness of sins.
All I could conclude perhaps one of the following:
1) Paul simply had a preference for the word CARIZOMAI
2) As Pauls letters were written some time before the Gospels and 1Jn, perhaps CARIZOMAI was being ‘replaced’ by AFIHMI as the most common word for forgive (seems unlikely as they are only a few decades apart)
3) There is something specific about the meaning of CARIZOMAI which Paul felt more adequately expressed how God has forgiven us and and we should forgive one another
I would appreciate any insights anyone has into this