“The concept of doing penance was introduced by Pope Callistus, who was Bishop of Rome in A.D. 217-222…” (310)

“Forgiveness normal exempts from punishment but by the Middle Ages the church taught that sins were not forgiven without satisfaction or compensation.” (311)

→ “normally exempts”? “private auricular confession to a priest was decreed to be a sacrament by the Fourth Lateran Council in 1215, and decreed by the Council of Trent in 1545 to be an ordinance of Christ necessary to salvation”

Jaenan, C.J. The apostles’ doctrine and fellowship: a documentary history of the early church and restorationist movements. Legas Publishing. 2003. p. 300.