The Seven Deadly Sins is a classification of the most objectionable vices which has been used since early Christian times to educate and instruct followers concerning (immoral) fallen man's tendency to sin. They are divided into two principal categories: "Venial sins", which are relatively minor, and could be forgiven through any Sacramentals or Sacraments of the church, and the more severe "Capital" or Mortal sins. Mortal sins destroyed the life of grace, and created the threat of eternal damnation unless either absolved through the sacrament of Confession, or forgiven through perfect contrition on the part of the penitent. Mortal sin, according to the beliefs of the Catholic Church is a sin that, unless confessed and absolved (or at least sacramental confession is willed if not available), condemns a person's soul to Hell after death. The Seven Deadly Sins are Lust, Gluttony, Greed, Sloth, Wrath, Envy, and Pride.

Lust is an inordinate craving for the pleasures of the body.

Gluttony is an inordinate desire to consume more than that which one requires.

Greed is the desire for material wealth or gain, ignoring the realm of the spiritual. It is also called Avarice or Covetousness.

Sloth is the avoidance of physical or spiritual work.

Wrath (also Anger, Rage) is manifested in the individual who spurns love and opts instead for fury.

Envy is the desire for other's traits, status, abilities, or situation.

Pride (also Vanity) is excessive belief in one's own abilities, that interferes with the individual's recognition of the grace of God. It has been called the sin from which all others arise.

However, modern terminology redefines terms used in The Seven Deadly Sins: Pride, Envy, Gluttony, Lust and the rest have become medical conditions. Instead of lust, we have “compulsive sexual behaviour”. Instead of gluttony, we have "eating disorders". Instead of envy, we have “low self-esteem”. Instead of wrath, we have “issues with anger management”.

In an attempt to give moral and ethical behavior more significance to current times, the Vatican has recently doubled the number of “deadly sins” from 7 to 14. They were published in an issue of the L'Osservatore Romano, the Vatican's official newspaper. The revision of the ldeadly sins comes after 1500 years, with Vatican officials explaining that the new items address a global "secular" society bent on the concerns in the age of globalization and the falling numbers of Roman Catholics going to confession. The Pope said that hedonism and consumerism had even invaded “the bosom of the Church itself, deeply undermining the Christian faith from within, and undermining the lifestyle and daily behaviour of believers”. He "wants every person to stop and think about their actions and how it affects not only their own soul but the community and the world at large.

These new sins include "bioethical" violations such as birth control, "morally dubious" experiments such as stem cell research, contributing to widening divide between rich and poor, excessive wealth, etc. and similar phenomena of the modern world. Human cloning, for example, could be considered a morally debatable experiment, and the Church has issued opinions on this issue before.