Jude 4 & 2 Pet 2:1
Jude 1:4 (NIV) For certain men whose condemnation was written about long ago have secretly slipped in among you. They are godless men, who change the grace of our God into a license for immorality and deny Jesus Christ our only Sovereign and Lord.
2Pet 2:1 (NIV) 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.