What criteria must be met before a person is considered to
be in mortal sin. Thank You and God Bless for this web-site
of wonderful info.
#1849 Sin is an offense against reason, truth, and right
conscience; it is failure in genuine love for God and neighbor
caused by a perverse attachment to certain goods. It
wounds the nature of man and injures human solidarity.
#1854 Sins are rightly evaluated according to their gravity.
The distinction between mortal and venial sin, already evident
in Scripture, became part of the tradition of the Church.
#1855 Mortal sin destroys charity in the heart of man by a
grave violation of God's law; it turns man away from God,
who is his ultimate end and his beatitude, by preferring an
inferior good to him.
Venial sin allows charity to subsist,
even though it offends and wounds it.
#1856 Mortal sin, by attacking the vital principle within us
- that is charity - necessitates a new initiative of God's
mercy and a conversion of heart which is normally
accomplished within the setting of the Sacrament of
#1857 For a sin to be mortal, three conditions must together
be met: Mortal sin is sin whose object is grave matter and
which is also committed with full knowledge and deliberate
#1858 Grave matter is specified by the Ten Commandments...
I hope these paragraphs taken from the Catechism of the
Catholic Church help.