Youcat commented through CCC – Question n. 316 - Part III.

YOUCAT Question n. 316 - Part III. How can we distinguish serious sins (mortal sins) from less serious (venial) sins?

(Youcat answer - repeated)  Serious sin destroys the divine power of love in a person’s heart, without which there can be no eternal beatitude. Hence it is also called mortal sin. Serious sin breaks with God, whereas venial sin only strains the relationship with him.

A deepening through CCC

(CCC 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 consent" (RP 17 § 12). (CCC 1858) Grave matter is specified by the Ten Commandments, corresponding to the answer of Jesus to the rich young man: "Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and your mother"  (Mk 10:19). The gravity of sins is more or less great: murder is graver than theft. One must also take into account who is wronged: violence against parents is in itself graver than violence against a stranger.     

Reflecting and meditating 

(Youcat comment) A serious sin cuts a person off from God. One requirement for such a sin is that it be opposed to an important value, for instance, directed against life or God (for example, murder, blasphemy, adultery, and so on) and that it be committed with full knowledge and full consent. Venial sins are opposed to secondary values (honor, truth, property, and so on) or are committed without full knowledge of their seriousness or without full consent of the will. Such sins disrupt the relationship with God but do not sever it.

(CCC Comment)

(CCC 1859) Mortal sin requires full knowledge and complete consent. It presupposes knowledge of the sinful character of the act, of its opposition to God's law. It also implies a consent sufficiently deliberate to be a personal choice. Feigned ignorance and hardness of heart (Cf. Mk 3:5-6; Lk 16:19-31) do not diminish, but rather increase, the voluntary character of a sin.     

(This question: How can we distinguish serious sins (mortal sins) from less serious (venial) sins? is continued)