'World' in the Bible

This is our [reason for] proud confidence: our conscience testifies that we have conducted ourselves in the world [in general], and especially toward you, with pure motives and godly sincerity, not in human wisdom, but in the grace of God [that is, His gracious lovingkindness that leads people to Christ and spiritual maturity].

among them the god of this world [Satan] has blinded the minds of the unbelieving to prevent them from seeing the illuminating light of the gospel of the glory of Christ, who is the image of God.

that is, that God was in Christ reconciling the world to Himself, not counting people’s sins against them [but canceling them]. And He has committed to us the message of reconciliation [that is, restoration to favor with God].

as unknown [to the world], yet well-known [by God and His people]; as dying, yet we live; as punished, yet not killed;

For [godly] sorrow that is in accord with the will of God produces a repentance without regret, leading to salvation; but worldly sorrow [the hopeless sorrow of those who do not believe] produces death.