Scripture didn't convince him. The power to absolve is clear in St. John (20: 20-23) "Whose sins ye shall forgive they are forgiven..." Other Bible references were used. Matt 16: 19, 18: 18.
He couldn't get out of his mind the idea that Jesus' crucifixion satisfied all sins forever. He also thought that confessing his sins to a friend was OK. I pray that in thinking over his arguments, he'll see how silly that one was. He will have to pray for understanding, as will we.
However, James told a story that I didn't know. In giving scriptural references for the forgiveness of sins, he said that the Old Testament gave the power to absolve and atone for sins, to the Jewish priests, and he told us the story of the "scapegoat."
A goat was chosen to be burden with the people's sins on the day of Atonement. The priest would confess the sins of the people (figuratively) on the head of the goat, whereupon the goat would be sent out into the wilderness. Hence the origin of the term "scapegoat."
Catholics believe that the sacrament of Reconciliation reinforces our faith in Jesus and the priest acts in persona Christi, in forgiving us our sins. Isn't it good and beautiful that Mother Church offers us this sacrament?