Ye adulteresses, know ye not that the friendship of the world is enmity with God? Whosoever therefore would be a friend of the world maketh himself an enemy of God.
John 15: 19
If ye were of the world, the world would love its own: but because ye are not of the world, but I chose you out of the world, therefore the world hateth you.
2 Tim 2: 4
No soldier on service entangleth himself in the affairs of this life; that he may please him who enrolled him as a soldier.
1 John 2: 15 - 17
Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him. 16 For all that is in the world, the lust of the flesh and the lust of the eyes and the vainglory of life, is not of the Father, but is of the world. 17 And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever.
2 Cor 6: 14 - 17
Be not unequally yoked with unbelievers: for what fellowship have righteousness and iniquity? or what communion hath light with darkness? 15 And what concord hath Christ with Belial? or what portion hath a believer with an unbeliever? 16 And what agreement hath a temple of God with idols? for we are a temple of the living God; even as God said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. 17 Wherefore come ye out from among them, and be ye separate, saith the Lord, and touch no unclean thing; and I will receive you.
Eph 5: 11
And have no fellowship with the unfruitful works of darkness, but rather even reprove them;
Romans 12: 2
And be not fashioned according to this world: but be ye transformed by the renewing of your mind, that ye may prove what is the good and acceptable and perfect will of God.