I. Sins are called mortal sins if they fulfill three conditions:

    1. A seriously sinful matter or something we think is a seriously sinful matter.
    2. We know that it is a serious matter.
    3. We fully consent to do it.

Mortal sins are indicated by the Sacred Scripture:
        John 5: 17. "There is sin unto death."
        Apocalypse 3: 1. "I know thy works: thou hast the name of being alive, and thou art dead."
        Galatians 5:19-21. "Now the works of the flesh are manifest: which are fornication, uncleanness, immodesty, luxury , idolatry, witchcrafts, enmities, contentions, emulations, wraths, quarrels, dissensions, sects, envies, murders, drunkenness, revellings, and such like. Of the which I foretell you, as I have foretold to you, that they who do such things shall not obtain the kingdom of God."

If a person does not know something is a mortal sin, although he did it, it is a faulty knowledge, he is not guilty of a mortal sin before God. However, it is a mortal sin materially or objectively speaking, although formally speaking, it is not. Formal mortal sin requires the person that he knows and fully consents to it. But God requires the person to find out what the law requires. We have to evaluate everything in our lives to see if it complies with the law.

II. Certain sins are always mortal sins. For example, (1) sins against God: blasphemy, rejecting the gift of the Catholic Faith, apostasy, heresy, schism; (2) all sins of impurity (adultery, fornication, masturbation, homosexual acts, willfully taking pleasure in impure thoughts, coveting someone's spouse, etc.; (3) certain other sins, e.g. willful murder, suicide, abortion, tubal ligations, vasectomy (for birth control reasons), artificial birth control.

III. Other sins can be venial or mortal depending on degree of seriousness of the act: stealing, lying, anger, neglect of one's obligations.

IV. Common mortal sins:
      1. Idolatry, both real idolatry and subtle idolatry such as pursuing things of this world at the  exclusion of the love and service of God.
      2. Failure to pursue the knowledge, love and service of God [due to the mode of life that lives only for this world, only for comfort and pleasure of this world] (Mark 12: 30)
      3. Living only for this world (100%) or primarily for this world (Luke 12: 19-20; James 4:4; Apocalypse 3: 15.)
      4. Failure to seek the True Faith. If one suspects that the Catholic Faith is a true faith and fails to do so is a mortal sin.
      5. Missing Sunday Masses.
      6. Unnecessary work on Sundays and Holy Days of obligation when work is unnecessary and willfully habitual.
      7. Shopping on Sundays (if it is frequent and long hours).
      8. Usurping the headship of the family without a good reason. (Husband allows himself to act so irresponsibly and childishly that his wife must run the family, would also commit a mortal sin.) This comes from the primacy of husband and father with respect to his wife and children. (Ephesians 5: 22-23).
      9. Suicide.
    10. Artificial birth control.
    11. Abortion.
    12. Tubal ligation and vasectomy.
    13. Adultery.
    14. Fornication (sexual intercourse between unmarried heterosexual partners).
    15. Incest.
    16. Rape.
    17. Concubinage or "living together" (Romans 13: 13-14, "not chambering").
    18. Masturbation.
    19. Homosexual acts.
    20. Impure thoughts and desire.
    21. Immodesty in dress (Matthew 5: 28)
            * Clothing should tend to conceal rather than to reveal.
            * it should not be transparent.
            * it should cover the knees.
            * it should cover the elbows.
            * avoid tight clothing.
            * neckline should be less than 2 finger's width below the pit of the throat.

    22. Prolonged kissing and holding hands if it arouses sexual desire.
    23. Reading pornographic books and materials; watching pornographic movies and TV shows.
    24. Grand theft harming the property of others.
    25. Coveting other people's spouses.
    26. Divorce without a good reason. Good reasons include one of the following: (a) one side commits adultery; (b) danger to one's life; (c) the other side prevents children from learning the Catholic Faith; (d) the other side prevents one to follow God.
    27. Remarriage after a divorce (even divorce with a good reason).
    28. Wife abuse.
    29. Child abuse.
    30. Child neglect.
    31. Drunkenness.
    32. Drug taking
    33. Wasting time (doing nothing, watching TV too much, neglecting one's duty).
    34. Profligacy.
    35. Lack of charity or selfishness.
    36. Sacrilegious Communion.
    37. Heresy.
    38. Apostasy. Apostasy stems from 3 sources:
            * living in mortal sins.
            * failure to study the faith.
            * failure to pray.

    39. Agnosticism which says that God is unknowable to man or unknowable by man. (Psalms 14: 1)
    40. Artificial insemination (test-tube fertilization, surrogate motherhood).
    41. Euthanasia (mercy-killing).

V. Dogmas of the Church concerning the consequences of unconfessed mortal sins.

    Pope Gregory X who chaired the Council of Lyons II in 1274 declared ex-cathedra that:

"The souls of those who die in mortal sin or with original sin only, however, immediately descend to hell, yet to be punished with different punishments." (Denzinger, Sources of Catholic Dogma, 30th Edition, # 464, p. 184)

"It (The Roman Church) teaches . . . that the souls . . . of those who die in mortal sin, or with only original sin descend immediately into hell;  however, to be punished with different penalties and in different places." (Denzinger, Op. Cit., 30th Edition, # 493a, p. 193)

Created 8:31 AM 2/10/98. This article: Feast of Holy Mother of God, January 1, 1998.