Proverbs 14:13 (NLT)
13Laughter can conceal a heavy heart, but when the laughter ends, the grief remains.
2 Peter 2:1 (NLT)
1But there were also false prophets in Israel, just as there will be false teachers among you. They will cleverly teach destructive heresies and even deny the Master who bought them. In this way, they will bring sudden destruction on themselves.