To understand this doctrine and practice
of the Church, it is
necessary to understand that sin has a double consequence.
Grave sin deprives us of communion with
God and therefore
makes us incapable of eternal life, the
privation of which is
called the "eternal punishment" of sin. On the other hand every sin, even venial, entails an
unhealthy attachment to creatures, which must be purified either here on earth, or
in the state called Purgatory. This purification frees one from what is called the "temporal punishment" of
sin. These two punishments must not be conceived of
as a kind of vengeance inflicted by God from without, but as following from the very nature of sin. A conversion which proceeds from a fervent charity can attain the complete
purification of the sinner in such a way that no punishment would remain.