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.
The conditions of history and of life are not to be considered the main impediment to human freedom. When man freely applies himself to the work of salvation, he finds sin the greatest obstacle.