The seven deadly sins, also known as the seven capital sins, include pride, avarice, lust, anger and gluttony. Envy and sloth also fall into this group. These sins are foundational because they are sins that people are especially prone to commit, and because they lead to most other sins.
Some Christians also designate these sins according to the virtues they oppose. For example, the capital sin of pride counters the virtue of humility, while lust counters the virtue of chastity. According to some theologians, at least some of the deadly sins, when willfully committed, cause the believer to lose the gift of sanctifying grace within and thus cause the individual to forfeit heaven.
Many Christians consider pride to be an especially deadly sin, because they believe that it was through pride that Lucifer (Satan) lost his place in heaven, and that it was also through the prideful desire to be like gods that Adam and Eve ate the fruit of the tree that God had forbade them to eat.
Lust likewise is a grave sin according to many theological systems. The sin of lust consists of willfully pursuing sexual pleasure outside the order of reason and outside of the order established by God.