2 Corinthians 11:13-15
for these are false apostles, deceitful workmen, disguised so as to pass for true apostles.
Galatians 2:4
and as to the false brethren, who insidiously crept in to spy out our liberty which we have by Christ Jesus, that they might bring us into servitude;
2 Timothy 3:8
Moses did not meet with greater opposition from Jannes and Jambres, than truth does from men so corrupted in their mind, and so adulterated in their faith.
2 Peter 2:1-2
As there were false prophets among the people of Israel, there will likewise be false doctors among you, who by introducing pernicious sects, and by renouncing the Lord, who bought them, will bring upon themselves swift destruction.