Ezekiel 44:23 (NKJV) 23 And they shall teach My people the difference between the holy and the unholy, and cause them to discern between the unclean and the clean.
Leviticus 18:3 (NKJV) 3 According to the doings of the land of Egypt, where you dwelt, you shall not do; and according to the doings of the land of Canaan, where I am bringing you, you shall not do; nor shall you walk in their ordinances.
Matthew 18:15-17 (NKJV) 15 “Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother. 16 But if he will not hear, take with you one or two more, that ‘by the mouth of two or three witnesses every word may be established.’ 17 And if he refuses to hear them, tell it to the church. But if he refuses even to hear the church, let him be to you like a heathen and a tax collector.
1 Corinthians 5:9-13 (NKJV) 9 I wrote to you in my epistle not to keep company with sexually immoral people. 10 Yet I certainly did not mean with the sexually immoral people of this world, or with the covetous, or extortioners, or idolaters, since then you would need to go out of the world. 11 But now I have written to you not to keep company with anyone named a brother, who is sexually immoral, or covetous, or an idolater, or a reviler, or a drunkard, or an extortioner–not even to eat with such a person. 12 For what have I to do with judging those also who are outside? Do you not judge those who are inside? 13 But those who are outside God judges. Therefore “put away from yourselves the evil person.”
1 Corinthians 6:15 (NKJV) 15 Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a harlot? Certainly not!
2 Corinthians 6:14-18 (NKJV) 14 Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness? 15 And what accord has Christ with Belial? Or what part has a believer with an unbeliever? 16 And what agreement has the temple of God with idols? For you are the temple of the living God. As God has said: “I will dwell in them And walk among them. I will be their God, And they shall be My people.” 17 Therefore “Come out from among them And be separate, says the Lord. Do not touch what is unclean, And I will receive you.” 18 “I will be a Father to you, And you shall be My sons and daughters, Says the LORD Almighty.”
2 Thessalonians 3:6 (NKJV) 6 But we command you, brethren, in the name of our Lord Jesus Christ, that you withdraw from every brother who walks disorderly and not according to the tradition which he received from us.
2 Thessalonians 3:14 (NKJV) 14 And if anyone does not obey our word in this epistle, note that person and do not keep company with him, that he may be ashamed.
1 Timothy 6:5 (NKJV) 5 useless wranglings of men of corrupt minds and destitute of the truth, who suppose that godliness is a means of gain. From such withdraw yourself.
2 Timothy 3:5 (NKJV) 5 having a form of godliness but denying its power. And from such people turn away!