Matthew 23:27

"'Woe to you, scribes and Pharisees, hypocrites! For you are like whitewashed tombs which indeed appear beautiful outwardly, but inside are full of dead men's bones and all uncleanness.'"

(That's pretty condemning. Jesus shows to not tolerate those who pretend to follow after Himself. It's one thing to be lost, it's a whole other thing to profess yourself a believer, but actually be lost.)