Of sacrifice to ritual, venial and involuntary sins,' and requires that the sacrifices should be offered at Jerusalem by the Aaronic priests; but these limitations did not belong to the older religion; and even in later times popular faith ascribed a larger efficacy to sacrifice.
It should be observed that the (also Augustinian) distinction between " deadly " and " venial " sins had a technical reference to the quasi-jural administration of ecclesiastical discipline, which grew gradually more organized as the spiritual power of the church established itself amid the ruins of the Western empire, and slowly developed into the theocracy that almost dominated Europe during the latter part of the middle ages.
" Deadly " sins were those for which formal ecclesiastical penance was held to be necessary, in order to save the sinner from eternal damnation; for " venial " sins he might obtain forgiveness, through prayer, almsgiving, and the observance of the regular fasts.
Treating this rule as axiomatic the Schoolmen elaborated their analyses of the sacrament of penance, distinguishing form and matter, attrition and contrition, mortal and venial sins.
It is common to go to confession, even though there are only venial sins to be confessed; and in order to excite contrition people are sometimes advised to confess over again some mortal sin from which they have been previously absolved.