2 Corinthians 6:14-18
14Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? 15And what concord hath Christ with Belial? or what part hath he that believeth with an infidel? 16And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. 17Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you. 18And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
Romans 12:2
2And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.
Titus 2:11-12
11For the grace of God that bringeth salvation hath appeared to all men, 12Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world;
John 17:15-16
15I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil. 16They are not of the world, even as I am not of the world.
John 15:19
19If ye were of the world, the world would love his own: but because ye are not of the world, but I have chosen you out of the world, therefore the world hateth you.
1 Peter 2:9
9But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light;
Leviticus 20:26
26And ye shall be holy unto me: for I the LORD am holy, and have severed you from other people, that ye should be mine.
Ephesians 5:11
11And have no fellowship with the unfruitful works of darkness, but rather reprove them.