'Sin' in the Bible

Now while I was speaking and praying, and confessing my sin and the sin of my people Israel, and presenting my supplication before the Lord my God in behalf of the holy mountain of my God,

“Seventy weeks have been decreed for your people and your holy city, to finish the transgression, to make an end of sin, to make atonement for iniquity, to bring in everlasting righteousness, to seal up vision and prophecy and to anoint the most holy place.