If you are referring to the wolves, they believe that grace is a license to sin. See 2 Peter 2.
It's unfortunate that one bad apple can spoil a whole barrel of good apples, but who are we to determine if someone is a wolf or sheep.
Jeremiah 17:9 - the human heart is desperately wicked and deceitful above all things
we have a hard time discerning ourselves let alone others whom we may interact with
and God says "do not judge by mere appearance, but make the right judgment" (at the heart of others that we can never see)
So, who among us are qualified to judge others? we are not qualified, let God be the judge
Share us a standard, is it the doctrine they believe in?
If we can never tell, then let God be the judge
As far as you know, the wheat and the chaff look so similar, we won't be able to tell the two apart
For now, let's give everyone the benefit of the doubt, and love others while guarding one's heart against falsehood.