For whomever does not know, has forgotten, willingly or unwillingly; or just plain does not presently care, mortal sin is:
- a sin of grave matter;
- committed with full knowledge;
- committed with deliberate consent.
1) Saint Paul on what mortal sins are:
“Adultery, fornication, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God” (Gal 5:19-20). Paul also tells the Corinthians, “know you not that the unjust shall not possess the kingdom of God? Do not err: neither fornicators, nor idolaters, nor adulterers, nor the effeminate, nor liars with mankind, nor thieves, nor covetous, nor drunkards nor railers, nor extortioners shall possess the kingdom of God” (1 Cor 6:9-10).
2) Sins of anger, blasphemy, envy, hatred, malice, murder, neglect of Sunday obligation, sins against faith, sins against hope, and sins against love.
3) Voluntary murder (Gen 4:10); the sin of impurity, i.e., sodomy and homosexual relations (Gen 18:20); taking advantage of the poor (Ex 2:23); and defrauding the workingman of his wages (James 5:4).
4) Pride, avarice, envy, wrath, lust, gluttony, and sloth.