(1 John 2:18-21) 18 Young children, it is the last hour, and, just as YOU have heard that antichrist is coming, even now there have come to be many antichrists; from which fact we gain the knowledge that it is the last hour. 19 They went out from us, but they were not of our sort; for if they had been of our sort, they would have remained with us. But [they went out] that it might be shown up that not all are of our sort. 20 And YOU have an anointing from the holy one; all of YOU have knowledge. 21 I write YOU, not because YOU do not know the truth, but because YOU know it, and because no lie originates with the truth.
(1 John 4:2-3) 2 YOU gain the knowledge of the inspired expression from God by this: Every inspired expression that confesses Jesus Christ as having come in the flesh originates with God, 3 but every inspired expression that does not confess Jesus does not originate with God. Furthermore, this is the antichrist’s [inspired expression] which YOU have heard was coming, and now it is already in the world.
(2 Peter 2:1-3) 2 However, there also came to be false prophets among the people, as there will also be false teachers among YOU. These very ones will quietly bring in destructive sects and will disown even the owner that bought them, bringing speedy destruction upon themselves. 2 Furthermore, many will follow their acts of loose conduct, and on account of these the way of the truth will be spoken of abusively. 3 Also, with covetousness they will exploit YOU with counterfeit words. But as for them, the judgment from of old is not moving slowly, and the destruction of them is not slumbering.
It appears the "signs and wonders" are such that some within the congregation, as well as without, will listen to them. Their teaching and exposition of belief seems to be from God. Yet their message is really opposed to what God wishes taught and practiced.
Think of the larger churches that attract so many today. They come from among those claiming to be Christ's brothers or "Christianity"
We can see a first century example here:
(Revelation 2:14-16) 14 “‘Nevertheless, I have a few things against you, that you have there those holding fast the teaching of Ba´laam, who went teaching Ba´lak to put a stumbling block before the sons of Israel, to eat things sacrificed to idols and to commit fornication. 15 So you, also, have those holding fast the teaching of the sect of Nic·o·la´us likewise. 16 Therefore repent. If you do not, I am coming to you quickly, and I will war with them with the long sword of my mouth.