καὶ οἱ χρώμενοι τὸν κόσμον ὡς μὴ καταχρώμενοι· παράγει γὰρ τὸ σχῆμα τοῦ κόσμου τούτου(1 Cor 7:31).
BDAG states that κόσμος in various texts possibly signifies:
(1) That which beautifies by means of external
(2) The universe
(3) All beings that exist above the level of animals
(4) Humanity in general
(5) "The system of human existence in its many aspects" (1 Cor 7:31a)
(6) The "world" that is hostile to God and His purposes (1 Jn 5:19)
(7) The collective aspect of an entity, i.e., totality or sum total.
The context of 1 Cor 7:31 suggests that the κόσμος under discussion is the framework of human existence "in its many aspects." This "system" is related to the ungodly world ruled by Satan but is not totally synonymous with it. The κόσμος mentioned in 7:31 potentially represents the sphere in which the "normal" everyday affairs of humanity occur: it takes in the educational, familial, social, economic and existential frameworks which we all now experience. This world, Paul writes, is ever "changing" (1 Cor 7:31).
Based on the context of 1 Cor 7:31, I would agree with the TEV rendering of this verse:
"those who deal in material goods, as though they were not fully occupied with them. For this world, as it is now, will not last much longer."
Compare 1 Cor 7:29.
Testament of Job 7:36: "The whole world shall perish, and its glory shall vanish, and all those who hold fast to it, will remain beneath, but my throne is in the upper world and its glory and splendor will be to the right of the Savior in the heavens."