Jewish views on sin

Judaism regards the violation of any of the 613 commandments as a sin. Judaism teaches that to sin is a part of life, since there is no perfect man and everyone has an inclination to do evil "from his youth". Sin has many classifications and degrees. Some sins are punishable with death by the court, others with death by heaven, others with lashes, and others without such punishment, but no sins committed with willful intentions go without consequence. Sins committed out of lack of knowledge are not considered sins, since a sin can't be a sin if the one who did it didn't know it was wrong. Unintentional sins are considered less severe sins.

When the Temple yet stood in Jerusalem, people would offer Karbanot (sacrifices) for their misdeeds. The atoning aspect of karbanot is carefully circumscribed. For the most part, karbanot only expiate unintentional sins, that is, sins committed because a person forgot that this thing was a sin or by error. No atonement is needed for violations committed under duress or through lack of knowledge, and for the most part, karbanot cannot atone for a malicious, deliberate sin. In addition, karbanot have no expiating effect unless the person making the offering sincerely repents of his or her actions before making the offering, and makes restitution to any person who was harmed by the violation.

The completely righteous (means a man who did nothing wrong in his life) enjoy in this life and in the life after. The not completely righteous or completely wicked) suffer for their sins in this world in order to atone for their sins through the humiliation, poverty, and suffering that God sends them. If the repentance is not complete in this world, the suffering will continue in the life after (hell). After the repentance is complete they join the righteous. The completely wicked (a man who did nothing good in his life) cannot correct their sins in this world or in the other, and hence do not suffer for them here, but in gehinom (hell). The very evil do not repent even at the gates of hell. Such people prosper in this world to receive their reward for any good deed, but cannot be cleansed by and hence cannot leave gehinom, because they don't or can't repent. This world can therefore seem unjust where the righteous suffer, while the wicked prosper. Many great thinkers have contemplated this, but God's justice is long, precise and just.

...
Wikipedia