1 But the Spirit explicitly says that in later times some will fall away from the faith, paying attention to deceitful spirits and doctrines of demons, 2 by means of the hypocrisy of liars seared in their own conscience as with a branding iron, (1 Timothy 4:1-2 NASB)
1 But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves. 2 Many will follow their sensuality, and because of them the way of the truth will be maligned; 3 and in their greed they will exploit you with false words; their judgment from long ago is not idle, and their destruction is not asleep. (2 Peter 2:1-3 NASB)
The greatest sin of those who reject Christ is their misrepresentation of the truth and the resultant deception. This is a work of Satan. His name means “adversary.” He is also called “the Devil.” This word in Greek means “the Slanderer.” Jesus called him a liar and a murderer. When we are in the battle against those who hate our faith and attack the veracity of the Word of God, there will be a commonality in their tactics. They misrepresent the truth, they lie, and they accuse God and us of all sorts of things that are untrue.