Venial sin

According to Roman Catholicism, a venial sin (meaning "forgivable" sin) is a lesser sin that does not result in a complete separation from God and eternal damnation in Hell. A venial sin involves a "temporary loss of grace" from God.

As the above criteria are the three criteria for mortal sin stated negatively (via de Morgan's theorem), a sin which met none of these extenuating conditions would necessarily be considered mortal.

Each venial sin that one commits adds to the penance that one must do. Penance left undone during life converts to punishment in purgatory. A venial sin can be left unconfessed.

Venial sins usually remain venial no matter how many one commits. They cannot "add up" to collectively constitute a mortal sin, except in certain cases of theft, where one steals a very small amount of money or goods many times.

In 1 John, the author distinguishes between two types of sin (1 John 5:16-17). According to a Roman Catholic commentary on the Bible, however, these verses do not refer precisely to venial and mortal sins. One class of sin leads to the loss of eternal life, but eternal life can be regained if a fellow Christian prays that the sinner be forgiven. The other class of sin leads to death, and the Christian is not instructed to pray that a fellow Christian be forgiven for such a sin. Since either class of sin puts one's eternal life in jeopardy, both would fall in the category of mortal sin.

The New Testament also mentions the unforgivable sin, blasphemy against the Holy Spirit (Mark 3:28-29).