'World' in the Bible

which has come to you. Indeed, just as in the whole world the gospel is constantly bearing fruit and spreading [by God’s power], just as it has been doing among you ever since the day you first heard of it and understood the grace of God in truth [becoming thoroughly and deeply acquainted with it].

See to it that no one takes you captive through philosophy and empty deception [pseudo-intellectual babble], according to the tradition [and musings] of mere men, following the elementary principles of this world, rather than following [the truth—the teachings of] Christ.

If you have died with Christ to the elementary principles of the world, why, as if you were still living in the world, do you submit to rules and regulations, such as,

For you died [to this world], and your [new, real] life is hidden with Christ in God.

Conduct yourself with wisdom in your interactions with outsiders (non-believers), make the most of each opportunity [treating it as something precious].