Sin is a religious issue defined in different ways among different traditions. Within the Christian traditions sin is any word or deed or thought against the eternal law. In addition it includes violations of God's will that do not count as moral offences, i.e. idolatry. It is indifference or opposition to the will of God, the refusal of faith and love. It is an explicit or implicit claim to live independently of God, to put something else, be it the world or self, in His place. Paul Tillich states that sin, as opposed to sins, is the all prevailing problem of one's life. It is a state of existence before it is an act. It is simultaneously willed and fated separation from self, others and the Ground of Being.
[Islam] In Islamic traditions sin has a variety of meanings. Sin is the evils which God's punishment brings. It is also moral guilt. It is unbelief and wrong actions proceeding from such unbelief. It is a wrong attitude to others and so injustice. The Koranic idea of sin seems to be that it is pride and opposition to God. This opposition to God may lead a man to be an atheist, a polytheist, or a simply careless irreligious person. Man does not inherit a sinful nature, but simply a weak one. Sin is not so much a disposition as a habit which men acquire because of their weakness.
[Shinto] In the Shinto tradition the term 'tsumi' most closely expresses the idea of sin. Tsumi includes three distinct categories, uncleanness, ill deeds and calamities. Ritual impurity, being dirty in body and clothing was want of respect for the gods. Calamities were regarded as signs of the displeasure of the gods for some offence, conscious or unconscious. Ill deeds for the ancient Japanese were divided into two broad categories, heavenly sins and earthly sins. Heavenly sins were breaking down the divisions of the rice fields, filling up the irrigation channels, opening the flood-gates of sluices, sowing bad seed over good, planting a magic wand in a rice field, flaying an animal alive and flaying backwards from tail to head, and evacuating excrements in places not meant for the purpose. Earthly sins were cutting the living skin, cutting the dead skin, white men (lepers and albinos), excrescences, a son's cohabitation with his own mother, a father's cohabitation with his own child, a father's cohabitation with his step-daughter, a man's cohabitation with his mother-in-law, cohabitation with animals, calamity through crawling worms (bites from snakes and other venomous creatures), calamity through the gods on high (like being struck by lightening), calamity through birds on high (soiling food), killing a neighbour's animal, and performing witchcraft.
[Catholic Church] Although he was made by God in a state of holiness, from the very dawn of history man abused his liberty, at the urging of the Evil One. Man set himself against God and sought to find fulfillment apart from God. "Through one man sin entered the world, and with sin death, death thus coming to all men inasmuch as all sinned" (Rom. 5,12). "It is human nature so fallen, stripped of the grace that clothed it, injured in its own natural powers and subjected to the dominion of death, that is transmitted to all men, and it is in this sense that every man is born in sin" (Paul VI, "Professio fidei," n. 16, AAS, 1968, p. 439). The multitude of sins, then, has become a sorrowful experience for humanity, and it is also the cause of manifold sorrows and ruin. One must not neglect the teaching on the nature and effects of personal sins, whereby man, acting knowingly and deliberately, by his act violates the moral law, and in a serious matter also seriously offends God.
The history of salvation is also the history of liberation from sin. Every intervention of God both in the Old and in the New Testament was to give guidance to men in the struggle against the forces of sin. The role entrusted to Christ in the history of salvation relates to the destruction of sin, and is fulfilled through the mystery of the cross. The profound reflections found in St. Paul (cf. Rom. 5) concerning the reality of sin and Christ's consequent "work of justice" must be numbered among the principal points of the Christian faith, and it is not right to pass over them in silence in catechesis. (Sacred Congregation for the Clergy, General Cathechetical Directory, 1971).
According to the witness concerning the beginning, sin in its original reality takes place in man's will-and conscience-first of all as "disobedience," that is, as opposition of the will of man to the will of God. This original disobedience presupposes a rejection, or at least a turning away from the truth contained in the Word of God, who creates the world. This Word is the same Word who was "in the beginning with God," who "was God," and without whom "nothing has been made of all that is," since "the world was made through him." (Papal Encyclical, Dominum et Vivificantem, 18 May 1986).