Antinomianism, which means being "anti-law," is a name for several views that have denied that God's law in Scripture should directly control the Christian's life.
Antinomianism is the heretical teaching that Salvation in Jesus rescues us from the guilt of sin but not the power of it, which results in an "it's all under the blood" attitude where one believes he is free to sin against God without compulsion or conviction to have remorse or to confess, or even repent.
Like most heresies, a simple scripture reading will easily dispute this teaching. Unfortunately, as with most heresies and false teachings, those who typically fall victim to them do not read the scriptures for themselves, have not truly been converted, or have some selfish gain from believing false teachings and want their "ears tickled."
In this case, if not ignorant of the Word of God, or a false convert, the notion of being "saved" and earmarked for heaven but still allowed to live in sin on earth is Satan's bait for the flesh, to which some bite.
Some may take this too far in the opposing direction and find themselves in the err of legalism. However, the Word of God is clear, and Truth is found right between these two falsehoods.
This false teaching has been around since Christ, and the Word of God addresses this issue directly in the following verses, making it clear to the reader that it is, in fact, false teaching.
"For certain individuals whose condemnation was written about long ago have secretly slipped in among you. They are ungodly people, who pervert the grace of our God into a license for immorality and deny Jesus Christ our only Sovereign and Lord." Jude 4
"But there were also false prophets among the people, just as there will be false teachers among you. They will secretly introduce destructive heresies, even denying the sovereign Lord who bought them—bringing swift destruction on themselves. 2 Many will follow their depraved conduct and will bring the way of truth into disrepute. 3 In their greed these teachers will exploit you with fabricated stories. Their condemnation has long been hanging over them, and their destruction has not been sleeping.
4 For if God did not spare angels when they sinned, but sent them to hell,[a] putting them in chains of darkness[b] to be held for judgment; 5 if he did not spare the ancient world when he brought the flood on its ungodly people, but protected Noah, a preacher of righteousness, and seven others; 6 if he condemned the cities of Sodom and Gomorrah by burning them to ashes, and made them an example of what is going to happen to the ungodly; 7 and if he rescued Lot, a righteous man, who was distressed by the depraved conduct of the lawless 8 (for that righteous man, living among them day after day, was tormented in his righteous soul by the lawless deeds he saw and heard)— 9 if this is so, then the Lord knows how to rescue the godly from trials and to hold the unrighteous for punishment on the day of judgment. 10 This is especially true of those who follow the corrupt desire of the flesh[c] and despise authority.
Bold and arrogant, they are not afraid to heap abuse on celestial beings; 11 yet even angels, although they are stronger and more powerful, do not heap abuse on such beings when bringing judgment on them from[d] the Lord. 12 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.
13 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.[e] 14 With eyes full of adultery, they never stop sinning; they seduce the unstable; they are experts in greed—an accursed brood! 15 They have left the straight way and wandered off to follow the way of Balaam son of Bezer,[f] who loved the wages of wickedness. 16 But he was rebuked for his wrongdoing by a donkey—an animal without speech—who spoke with a human voice and restrained the prophet’s madness.
17 These people are springs without water and mists driven by a storm. Blackest darkness is reserved for them. 18 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. 19 They promise them freedom, while they themselves are slaves of depravity—for “people are slaves to whatever has mastered them.” 20 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. 21 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. 22 Of them the proverbs are true: “A dog returns to its vomit,”[g] and, “A sow that is washed returns to her wallowing in the mud.”
2 Peter 2