2 Corinthians 6:14-18 
Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?  
And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?  
And 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.  
Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you.  
And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
Leviticus 20:26 
And ye shall be holy unto me: for I the LORD am holy, and have severed you from other people, that ye should be mine.
1 Peter 1:15-16  
But as he which hath called you is holy, so be ye holy in all manner of conversation;  
Because it is written, Be ye holy; for I am holy.
Romans 16:17  
Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them.
2 John 1:10-11
If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed:  
For he that biddeth him God speed is partaker of his evil deeds.
James 4:4 
Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God? whosoever therefore will be a friend of the world is the enemy of God.
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.  
For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.  
And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever.
Psalm 1:1 
Blessed is the man that walketh not in the counsel of the ungodly, nor standeth in the way of sinners, nor sitteth in the seat of the scornful.
Romans 12:1-2
I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.  
And 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.
Exodus 20:3-6 
Thou shalt have no other gods before me.  
Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth:  
Thou shalt not bow down thyself to them, nor serve them: for I the LORD thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me;  
And shewing mercy unto thousands of them that love me, and keep my commandments.
Joshua 24:14-15 
Now therefore fear the LORD, and serve him in sincerity and in truth: and put away the gods which your fathers served on the other side of the flood, and in Egypt; and serve ye the LORD.  
And if it seem evil unto you to serve the LORD, choose you this day whom ye will serve; whether the gods which your fathers served that were on the other side of the flood, or the gods of the Amorites, in whose land ye dwell: but as for me and my house, we will serve the LORD.
Matthew 25:31-32  
When the Son of man shall come in his glory, and all the holy angels with him, then shall he sit upon the throne of his glory:  
And before him shall be gathered all nations: and he shall separate them one from another, as a shepherd divideth his sheep from the goats.