'World' in the Bible

Pure religion and undefiled before our God and Father is this: to visit the fatherless and widows in their affliction, and to keep oneself unstained by the world.

Listen, my beloved brothers. Didn't God choose those who are poor in this world to be rich in faith, and heirs of the Kingdom which he promised to those who love him?

And the tongue is a fire. The world of iniquity among our members is the tongue, which defiles the whole body, and sets on fire the course of nature, and is set on fire by Gehenna.

You adulterers and adulteresses, don't you know that friendship with the world is enmity with God? Whoever therefore wants to be a friend of the world makes himself an enemy of God.