1 Corinthians 5:9-11
I wrote you in my letter not to associate with sexually immoral people. / I was not including the sexually immoral of this world, or the greedy and swindlers, or idolaters. In that case you would have to leave this world. / But now I am writing you not to associate with anyone who claims to be a brother but is sexually immoral or greedy, an idolater or a verbal abuser, a drunkard or a swindler. With such a man do not even eat.

2 Corinthians 6:14-17
Do not be unequally yoked with unbelievers. For what partnership can righteousness have with wickedness? Or what fellowship does light have with darkness? / What harmony is there between Christ and Belial? Or what does a believer have in common with an unbeliever? / What agreement can exist between the temple of God and idols? For we are the temple of the living God. As God has said: “I will dwell with them and walk among them, and I will be their God, and they will be My people.” ...

Romans 16:17-18
Now I urge you, brothers, to watch out for those who create divisions and obstacles that are contrary to the teaching you have learned. Turn away from them. / For such people are not serving our Lord Christ, but their own appetites. By smooth talk and flattery they deceive the hearts of the naive.

1 Corinthians 15:33
Do not be deceived: “Bad company corrupts good character.”

1 John 1:6-7
If we say we have fellowship with Him yet walk in the darkness, we lie and do not practice the truth. / But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin.

1 John 2:15-17
Do not love the world or anything in the world. If anyone loves the world, the love of the Father is not in him. / For all that is in the world—the desires of the flesh, the desires of the eyes, and the pride of life—is not from the Father but from the world. / The world is passing away, along with its desires; but whoever does the will of God remains forever.

2 Thessalonians 3:6
Now we command you, brothers, in the name of our Lord Jesus Christ, to keep away from any brother who leads an undisciplined life that is not in keeping with the tradition you received from us.

2 Thessalonians 3:14-15
Take note of anyone who does not obey the instructions we have given in this letter. Do not associate with him, so that he may be ashamed. / Yet do not regard him as an enemy, but admonish him as a brother.

Proverbs 4:14-15
Do not set foot on the path of the wicked or walk in the way of evildoers. / Avoid it; do not travel on it. Turn from it and pass on by.

Psalm 1:1
Blessed is the man who does not walk in the counsel of the wicked, or set foot on the path of sinners, or sit in the seat of mockers.

2 John 1:10-11
If anyone comes to you but does not bring this teaching, do not receive him into your home or even greet him. / Whoever greets such a person shares in his evil deeds.

1 Timothy 5:22
Do not be too quick in the laying on of hands and thereby share in the sins of others. Keep yourself pure.

1 Peter 4:3-4
For you have spent enough time in the past carrying out the same desires as the Gentiles: living in debauchery, lust, drunkenness, orgies, carousing, and detestable idolatry. / Because of this, they consider it strange of you not to plunge with them into the same flood of reckless indiscretion, and they heap abuse on you.

Colossians 3:5-7
Put to death, therefore, the components of your earthly nature: sexual immorality, impurity, lust, evil desires, and greed, which is idolatry. / Because of these, the wrath of God is coming on the sons of disobedience. / When you lived among them, you also used to walk in these ways.

1 Thessalonians 5:22
Abstain from every form of evil.