Don’t be so quick to bash the priest.
No bashing…
My understanding is limited, but I believe back then, they understood the threshold for sin becoming mortal sin was much higher. When sacramental confession was conferred, it was done publicly for grievous sins, and long term sometimes life long penances were required.
Yes SOME mortal sins were in a very strict category and required …depending on the time and place …very long term penances…such as Apostasy ,Adultery, Murder, Idolotry. But this does not mean that other mortal sins did not require confession…but yes it is true that SOME were put in the very very serious category…similar in a sense to those we put under excommunication today…
This was of course during a time of persecution, where really only those truly devoted to our lord joined the faith. The common mortal sins of today, such as adultery, fornication and birth control, would probably have not been an issue among such Christians in those days.
Actually adultery would be one of them mentioned above for which very serious penance etc could be imposed…fornication of course was seen as serious Paul was VERY serious about such…and to other mortal sins (he lists various things that separate one from the Kingdom of God…not an exhaustive list of course) …and one finds references to “Birth control” as well in the earliest writings as something that represented the “way of death” (this is their language)…along with the others mentioned here…and many others as well…