Christian views of sin are mostly understood as legal infraction or contract violation, and so salvation tends to be viewed in legal terms, similar to Jewish thinking.
The Bible portrays sin as rejecting God as the lord of the universe. Defining sin based on the account of Adam and Eve in the Book of Genesis who showed their rejection of God by eating the fruit of the Tree of the Knowledge of Good and Evil, this act being a visual illustration of their desire to determine what is right and wrong (having knowledge of good and evil) rather than God fulfilling this role. In Eastern Christianity, sin is viewed in terms of its effects on relationships, both among people and between people and God.
In a New Testament biblical sense, sin is actually defined in 1 John 3:4 "Whoever sins breaks the law. In fact, sin is lawlessness". In the biblical sense sin is NOT law breaking, but reveals our sinfulness, lawlessness or disregard for God's law. The Law mentioned here is referring to God's rule over all creation. Sin and sins are not the same. Where sin appears to be the fundamental problem or disease that mankind shares, sins are the symptoms of that disease revealing themselves as transgressions of the law.
Thus, the moment Adam and Eve ate the fruit from the tree—which God had commanded them not to do—sinful death was born; it was an act of disobedience, thinking they could become like gods, that was the sin. Since Adam was the head of the human race, he is held responsible for the evil that took place, for which reason the Fall of man is referred to as the "sin of Adam". This sin caused Adam and his descendants to lose unrestricted access to God Himself. The years of life were limited. "Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned" (Romans 5:12). In Christian theology, the death of Jesus on the cross is the atonement to the sin of Adam. "For as in Adam all die, even so in Christ shall all be made alive." (1 Corinthians 15:22). As a result of that act of Christ, all who put their trust in Christ alone now have unrestricted access to God through prayer and in presence.
The Greek word in the New Testament that is translated in English as "sin" is hamartia, which literally means missing the target. 1 John 3:4 states: "Everyone who sins breaks the law; in fact, sin is lawlessness". Jesus clarified the law by defining its foundation: "Jesus replied: 'Love the Lord your God with all your heart and with all your soul and with all your mind.' This is the first and greatest commandment. And the second is like it: 'Love your neighbor as yourself.' All the Law and the Prophets hang on these two commandments." (Matthew 22:36-40)
"All the Law" could refer to the Ten Commandments in Exodus 20:1-17 that God demands of those that follow Him. In Christianity, salvation is viewed in terms of reconciliation and a genuine relationship with Christ. In Romans 6:23 it says, "the wages of sin is death, but the gift of God is eternal life in Christ our Lord". Both Eastern and Western Christians agree, on the basis of Scripture, that sin serves as a barrier to one having a complete relationship with God. But in the Gospel of John 3:16 it states "For God so loved the world, He gave his only begotten son that whosoever believes in Him shall not perish but have everlasting life." This verse is a common base of Christianity (see article on John 3:16). Some Christian denominations believe that salvation is not obtained through good works but faith alone evidenced by obedience to the laws of their denomination. These Christians believe that humanity falls short of the 'perfect glory' of God because of sins (imperfections), but the sacrifice of the messiah Jesus provides the potential for redemption (Romans 3:23-24). See also Biblical law in Christianity.
Mortal sins are sins of grave (serious) matter, where the sinner is fully aware that the act (or omission) is both a sin and a grave matter, and performs the act (or omission) with fully deliberate consent. The act of committing a mortal sin cuts off the sinner from God's grace; it is in itself a rejection of God. If left un-reconciled, mortal sins result in eternal punishment in Hell.
Venial sins are sins which do not meet the conditions for mortal sins. The act of committing a venial sin does not cut off the sinner from God's grace, as the sinner has not rejected God. However, venial sins do injure the relationship between the sinner and God, and as such, must be reconciled to God, either through the sacrament of reconciliation or receiving the Eucharist.
Both mortal and venial sins have a dual nature of punishment. They incur both guilt for the sin, yielding eternal punishment, and temporal punishment for the sin. Reconciliation is an act of God's mercy, and addresses the guilt and eternal punishment for sin. Purgatory and indulgences address the temporal punishment for sin, and exercise of God's justice.
Roman Catholic doctrine also sees sin as being twofold: Sin is, at once, any evil or immoral action which infracts God's law and the inevitable consequences, the state of being that comes about by committing the sinful action. Sin can and does alienate a person both from God and the community. Hence, the Catholic Church's insistence on reconciliation with both God and the Church itself.
The Roman Catholic view of sin has recently expanded. Monsignor Gianfranco Girotti, Regent of the Catholic Apostolic Penitentiary, has said that "known sins increasingly manifest themselves as behavior that damages society as a whole," including, for example:
Mortal sins, which are any severe and intentional actions that directly disobey God, are often confused with the seven deadly sins, which are pride, envy, lust, anger, greed, sloth and gluttony. They are not, however, the same.
Sin is differentiated from the relativistic, individualized transgressions of moral standards pure human rationale dictates, by secular humanism, by its immutability and everlasting nature. Sin never changes, but popular notion does. Hence, sin will always be sin, regardless of epoch.
Religions other than Roman Catholicism view the concept of sin as a wandering from the path to enlightenment, and this also applies to Roman Catholicism, with the addition that God is a Person, and is unchanging; The Father by which everything in three dimensional reality is defined. What is contrary to the Will of God is sin.
Humankind is the only thing that can sin because free will is required, and with the exception of humans, everything in the Universe perfectly obeys the Will of God. The predictability of all things created belies the nature of all things as being ordered according to time, measure, and weight; as recorded in The Holy Bible. Relative physics adopted this view of the Universe and refers to the second, meter, and kilogram as the foundation of all three dimensional reality.
In the grand scheme of everything, from beginning to end, God's Will must be done. By this measure sin can be viewed as the wraith of primordial guilt, or original sin.
The term sin is only applicable to competent individuals past the age of reason. If a person doesn't know something is contrary to the Will of God they cannot be held accountable for sin until such time comes that the individual understands that particular sin is wrong.
This doesn't always happen during the temporal, physical, organic life of the physical body. In this instance the person will be illuminated after death, at which point the soul will be aware of exactly what sins they are guilty of. Atonement for sin cannot be made after the physical death of the human organism, and thus the soul of the unrepentant sinner is in an impossible predicament of final annihilation from existence.
However, God is not bound by time, and if a person was ever forgiven, they were always forgiven. And such is the nature of all Roman Catholics to pray for the departed soul, who didn't understand sin while physical life was in his/her flesh.
Roman Catholic Doctrine dictates Jesus Christ alone can forgive sin, although sin need only be forgiven if one desires immortality in everlasting paradise.
Many Protestants teach that, due to original sin, humanity has lost any and all capacity to move towards reconciliation with God (Romans 3:23;6:23; Ephesians 2:1-3); in fact, this inborn sin turns humans away from God and towards themselves and their own desires (Isaiah 53:6a). Thus, humans may be brought back into a relationship with God only by way of God's rescuing the sinner from his/her hopeless condition (Galatians 5:17-21; Ephesians 2:4-10) through Jesus's ransom sacrifice (Romans 5:6-8; Colossians 2:13-15). Salvation is sola fide (by faith alone); sola gratia (by grace alone); and is begun and completed by God alone through Jesus (Ephesians 2:8,9). This understanding of original sin (Romans 5:12-19), is most closely associated with Calvinism (see total depravity) and Lutheranism. Calvinism allows for the "goodness" of humanity through the belief in God's common grace. Methodist theology adapts the concept by stating that humans, entirely sinful and totally depraved, can only "do good" through God's prevenient grace.
This is in contrast to the Catholic teaching that while sin has tarnished the original goodness of humanity prior to the Fall, it has not entirely extinguished that goodness, or at least the potential for goodness, allowing humans to reach towards God to share in the Redemption which Jesus Christ won for them. Some non-Catholic or Orthodox groups hold similar views.
There is dispute about where sin originated. Some who interpret the king of Tyre in Ezekiel 28 as a symbol for Satan believe sin originated when Satan coveted the position that rightfully belongs to God. The origin of individual sins is discussed in James 1:14-15 - "14but each one is tempted when, by his own evil desire, he is dragged away and enticed. 15Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death."(NIV)
Within some branches of Protestantism, there are several defined types of sin (as in Roman Catholicism):
The Eastern Orthodox and Oriental Orthodox use sin both to refer to humanity's fallen condition and to refer to individual sinful acts. In many ways the Orthodox Christian view of sin is similar to the Jewish, although neither form of Orthodoxy makes formal distinctions among "grades" of sins.
The Eastern Catholic Churches, which derive their theology and spirituality from same sources as the Eastern Orthodox and Oriental Orthodox, do not use the Latin Catholic distinction between Mortal and Venial sin. However, like the Eastern and Oriental Orthodox, the Eastern Catholic Churches do make a distinction between sins that are serious enough to bar one from Holy Communion (and must be confessed before receiving once again) and those which are not sufficiently serious to do so. In this respect, the Eastern Tradition is similar to the Western, but the Eastern Churches do not consider death in such a state to automatically mean damnation to Hell.
Within the emerging church movement and other progressive forms of Christianity, the definition of "sin" may or may not be central to an understanding of Christianity and its relationship to society. This non-dogmatic formulation of sin is perhaps more characteristic of the post-modern fluid views of the emerging church. Sin in this context can have multiple meanings, including but not limited to interpersonal sins (harming one's neighbours, friends, or families with negative actions), environmental sins (pollution, overconsumption), structural sins (homophobia or heterosexism, misogyny, racism, etc.), or even personal sins (actions which are harmful to oneself). As a result of this re-interpretation of the traditional concept of sin, new concepts of liberation and salvation are required.
In Christianity, atonement can refer to the redemption achieved by Jesus Christ by his virgin birth, sinless life, crucifixion, and resurrection, thereby fulfilling more than 300 Old Testament prophecies. Its centrality to traditional interpretations of Christian theology means that it has been the source of much discussion and some controversy throughout Christian history. Generally it is understood that the death of Jesus Christ was a sacrifice that relieves believers of the burden of their sins. However, the actual meaning of this precept is very widely debated. The traditional teaching of some churches traces this idea of atonement to blood sacrifices in the ancient Hebraic faith.
Christian theologians have presented different interpretations of atonement:
The ideas of these and other Christian theologians can be summed up under these rubrics: