A. Avoid intimate fellowship with the worldly:

EPH 5:11. And have no fellowship with the unfruitful works of darkness, but rather reprove them.

2COR 6:14. Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?

2COR 6:15. And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?

2COR 6:16. 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.

2COR 6:17. Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you.

JOH 15:19. If 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.

1COR 10:20. But I say, that the things which the Gentiles sacrifice, they sacrifice to devils, and not to God: and I would not that ye should have fellowship with devils.

1COR 10:21. Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lord's table, and of the table of devils.

1JOH 5:19. And we know that we are of God, and the whole world lieth in wickedness.

B. We cannot avoid some dealings with unbelievers:

JOH 17:15. I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil.

1COR 5:9. I wrote unto you in an epistle not to company with fornicators:

1COR 5:10. Yet not altogether with the fornicators of this world, or with the covetous, or extortioners, or with idolaters; for then must ye needs go out of the world.

C. Use fellowship with unbelievers to win them:

MAT 9:9. And as Jesus passed forth from thence, he saw a man, named Matthew, sitting at the receipt of custom: and he saith unto him, Follow me. And he arose, and followed him.

MAT 9:10. And it came to pass, as Jesus sat at meat in the house, behold, many publicans and sinners came and sat down with him and his disciples.

MAT 9:11. And when the Pharisees saw it, they said unto his disciples, Why eateth your Master with publicans and sinners?

MAT 9:12. But when Jesus heard that, he said unto them, They that be whole need not a physician, but they that are sick.

MAT 9:13. But go ye and learn what that meaneth, I will have mercy, and not sacrifice: for I am not come to call the righteous, but sinners to repentance.

1COR 10:27. If any of them that believe not bid you to a feast, and ye be disposed to go; whatsoever is set before you, eat, asking no question for conscience sake.