They are called Deadly Sins, to the series of vices punished by Christianity, because they corrupted the purity of human feelings. They were adopted, mainly, to educate the followers of this religion about the actions that they should not commit. Great religious figures, such as Cipriano de Carthage and San Gregorio Magno, wrote about the perversions that plagued the human mind; however, the purpose of these writings was to warn the monks about the behaviors they should not take while in the service of God, urging them to maintain proper and joyful conduct. They are called capitals because other sins are generated from them.
The first list of capital sins consisted of eight perversions and was divided into two groups, the first being the one in which the vices of possession were found and the second the irascible vices. Gluttony and drunkenness, lust, avarice and vainglory, were those represented by the desire to possess objects and individuals for the pleasure they could provide; meanwhile, anger, sadness, laziness and pride, are seen as directly affecting behavior. Around the 5th century, the list was reduced to 7 sins and this was finally accepted; It was composed of: lust, laziness, gluttony, anger, envy, greed and pride.
Historically, there is no really reliable source regarding the capital sins, since the conception of them today comes mostly from religious literary creations (for example, the Divine Comedy, by Dante Alighieri). However, the idea of vices themselves has not changed much throughout history. They have even come to be related to demons such as Asmodeus, Mammon, Beelzebub, Leviathan, Lucifer, Amon and Belphegor.
For its part, lust is described as the unbridled desire to have sex outside of marriage or, well, to be unfaithful during it. Gluttony deals with overeating and the abuse of alcoholic beverages. Meanwhile, greed discredits the activity of acquiring many goods or wanting them desperately. Laziness, different from what is popularly thought, does not speak about leisure or laziness itself, but about the feeling of wanting to be apart from religion. Anger, likewise, is the hatred and uncontrolled anger that is experienced in a stressful situation, motivated by revenge. The concept of envy refers to the desire to have the goods or physical and psychological characteristics of someone else. Pride, the most serious of all sins, is excessive love for one's own being, resulting in self-pride.