They are headed for destruction and the want to take you with them.
Matthew 7:15, 22-23 "Beware of false prophets who come disguised as harmless sheep but are really vicious wolves.
22 On judgment day many will say to Me, 'Lord! Lord! We prophesied in Your name and cast out demons in Your name and performed many miracles in Your name.' 23 But I will reply, 'I never knew you. Get away from Me, you who break God's laws.'
Mark 12:38-40 Jesus also taught: "Beware of these teachers of religious law! For they like to parade around in flowing robes and receive respectful greetings as they walk in the marketplaces. 39 And how they love the seats of honor in the synagogues and the head table at banquets. 40 Yet they shamelessly cheat widows out of their property and then pretend to be pious by making long prayers in public. Because of this, they will be more severely punished."
2 Corinthians 11:13-15 These people are false apostles. They are deceitful workers who disguise themselves as apostles of Christ. 14 But I am not surprised! Even Satan disguises himself as an angel of light. 15 So it is no wonder that his servants also disguise themselves as servants of righteousness. In the end they will get the punishment their wicked deeds deserve.
The world has never been in short supply of deceivers. Promoters of false teaching have been around since the Garden of Eden when a thin disguise was all it took to bring sin into the world. The father of lies (John 8:44) has been busy for a long time, he has developed disguises that are much better than the one that he used in the garden, I don't think that a talking snake would be a very clever disguise in the year 2010. But that's okay because now he has people that look a lot like God's people to help him out.
Satan has "apostles, the prophets, the evangelists, and the pastors and teachers" just like God has. The "apostles, the prophets, the evangelists, and the pastors and teachers" that belong to God are supposed to equip God's people to resist the devil, their duty is to build up believers to become mature so that they won't fall for the devils tricks. (Ephesians 4:11-14)
I must beware of the tricks of the devil, he will come around disguised as one of God's "apostles, the prophets, the evangelists, and the pastors and teachers" but their desire is to cause me harm and cause to to rebel against God. They look good, they sound good but they are interested in their own gain and in pulling me away from the truth.
Thank you Lord for your love and mercy, I pray that I will always be on guard against the deceiver and his subtle lies.
You might like to read: Commands of Jesus blog series.