Please do. I am actually genuinely interested in how these Christians would defend their actions.
Alright. I'll place these scriptures in chronological order according to L. Michael White's
From Jesus to Christianirty. Other scholars may vary the order somewhat.
Please note the shift in tone over time.
The II Peter passage is pretty much the nadir, but the irony of the passages in II and III John placed side-by-side is interesting.
Anyway...
Philippians 1: 15-18: "It is true that some preach Christ out of envy and rivalry, but others out of goodwill. The latter do so out of love, knowing that I am put here for the defense of the gospel. The former preach Christ out of selfish ambition, not sincerely, supposing that they can stir up trouble for me while I am in chains. But what does it matter? The important thing is that in every way, whether from false motives or true, Christ is preached. And because of this I rejoice."
Galatians 1:6-9: "I am astonished that you are so quickly deserting the one who called you to live in the grace of Christ and are turning to a different gospelwhich is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ. But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let them be under Gods curse! As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let them be under Gods curse!"
II Corinthians 11:12-15: "And I will keep on doing what I am doing in order to cut the ground from under those who want an opportunity to be considered equal with us in the things they boast about. For such people are false apostles, deceitful workers, masquerading as apostles of Christ. And no wonder, for Satan himself masquerades as an angel of light. It is not surprising, then, if his servants also masquerade as servants of righteousness. Their end will be what their actions deserve."
Romans 15:17-19: "I urge you, brothers and sisters, to watch out for those who cause divisions and put obstacles in your way that are contrary to the teaching you have learned. Keep away from them. For such people are not serving our Lord Christ, but their own appetites. By smooth talk and flattery they deceive the minds of naive people. Everyone has heard about your obedience, so I rejoice because of you; but I want you to be wise about what is good, and innocent about what is evil."
Colossians 2:16-19: "Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. These are a shadow of the things that were to come; the reality, however, is found in Christ. Do not let anyone who delights in false humility and the worship of angels disqualify you. Such a person also goes into great detail about what they have seen; they are puffed up with idle notions by their unspiritual mind. They have lost connection with the head, from whom the whole body, supported and held together by its ligaments and sinews, grows as God causes it to grow."
II Thessalonians 3:14,15: "Take special note of anyone who does not obey our instruction in this letter. Do not associate with them, in order that they may feel ashamed. Yet do not regard them as an enemy, but warn them as you would a fellow believer.
Jude 1:8-13: In the very same way, on the strength of their dreams these ungodly people pollute their own bodies, reject authority and heap abuse on celestial beings...Yet these people slander whatever they do not understand, and the very things they do understand by instinctas irrational animals dowill destroy them. Woe to them! They have taken the way of Cain; they have rushed for profit into Balaams error; they have been destroyed in Korahs rebellion. These people are blemishes at your love feasts, eating with you without the slightest qualmshepherds who feed only themselves. They are clouds without rain, blown along by the wind; autumn trees, without fruit and uprootedtwice dead. They are wild waves of the sea, foaming up their shame; wandering stars, for whom blackest darkness has been reserved forever."
I timothy 1:8-11 &18-20: We know that the law is good if one uses it properly. We also know that the law is made not for the righteous but for lawbreakers and rebels, the ungodly and sinful, the unholy and irreligious, for those who kill their fathers or mothers, for murderers, for the sexually immoral, for those practicing homosexuality, for slave traders and liars and perjurersand for whatever else is contrary to the sound doctrine that conforms to the gospel concerning the glory of the blessed God, which he entrusted to me."
"Timothy, my son, I am giving you this command in keeping with the prophecies once made about you, so that by recalling them you may fight the battle well, holding on to faith and a good conscience, which some have rejected and so have suffered shipwreck with regard to the faith. Among them are Hymenaeus and Alexander, whom I have handed over to Satan to be taught not to blaspheme."
II timothy 3:1-9: "But mark this: There will be terrible times in the last days. People will be lovers of themselves, lovers of money, boastful, proud, abusive, disobedient to their parents, ungrateful, unholy, without love, unforgiving, slanderous, without self-control, brutal, not lovers of the good, treacherous, rash, conceited, lovers of pleasure rather than lovers of God having a form of godliness but denying its power. Have nothing to do with such people. They are the kind who worm their way into homes and gain control over gullible women, who are loaded down with sins and are swayed by all kinds of evil desires, always learning but never able to come to a knowledge of the truth. Just as Jannes and Jambres opposed Moses, so also these teachers oppose the truth. They are men of depraved minds, who, as far as the faith is concerned, are rejected. But they will not get very far because, as in the case of those men, their folly will be clear to everyone.
Titus 1:10-16: "For there are many rebellious people, full of meaningless talk and deception, especially those of the circumcision group. They must be silenced, because they are disrupting whole households by teaching things they ought not to teachand that for the sake of dishonest gain. One of Cretes own prophets has said it: Cretans are always liars, evil brutes, lazy gluttons. This saying is true. Therefore rebuke them sharply, so that they will be sound in the faith and will pay no attention to Jewish myths or to the merely human commands of those who reject the truth. To the pure, all things are pure, but to those who are corrupted and do not believe, nothing is pure. In fact, both their minds and consciences are corrupted. They claim to know God, but by their actions they deny him. They are detestable, disobedient and unfit for doing anything good."
II Peter 2:10-22: "Bold and arrogant, they are not afraid to heap abuse on celestial beings; yet even angels, although they are stronger and more powerful, do not heap abuse on such beings when bringing judgment on them from the Lord. But these people blaspheme in matters they do not understand. They are like unreasoning animals, creatures of instinct, born only to be caught and destroyed, and like animals they too will perish. They will be paid back with harm for the harm they have done. Their idea of pleasure is to carouse in broad daylight. They are blots and blemishes, reveling in their pleasures while they feast with you. With eyes full of adultery, they never stop sinning; they seduce the unstable; they are experts in greedan accursed brood! They have left the straight way and wandered off to follow the way of Balaam son of Bezer, who loved the wages of wickedness. But he was rebuked for his wrongdoing by a donkeyan animal without speechwho spoke with a human voice and restrained the prophets madness. These people are springs without water and mists driven by a storm. Blackest darkness is reserved for them. For they mouth empty, boastful words and, by appealing to the lustful desires of the flesh, they entice people who are just escaping from those who live in error. They promise them freedom, while they themselves are slaves of depravityfor people are slaves to whatever has mastered them. If they have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ and are again entangled in it and are overcome, they are worse off at the end than they were at the beginning. It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them. Of them the proverbs are true: 'A dog returns to its vomit,' and, 'A sow that is washed returns to her wallowing in the mud.'"
II John 1:7-11: "I say this because many deceivers, who do not acknowledge Jesus Christ as coming in the flesh, have gone out into the world. Any such person is the deceiver and the antichrist. Watch out that you do not lose what we have worked for, but that you may be rewarded fully. Anyone who runs ahead and does not continue in the teaching of Christ does not have God; whoever continues in the teaching has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not take them into your house or welcome them. Anyone who welcomes them shares in their wicked work."
III John 1:9-10: "I wrote to the church, but Diotrephes, who loves to be first, will not welcome us. So when I come, I will call attention to what he is doing, spreading malicious nonsense about us. Not satisfied with that, he even refuses to welcome other believers. He also stops those who want to do so and puts them out of the church."