Have you ever heard the phrase, talks out both sides of his mouth?
I usually think of politicians. It refers to someone that tells me one thing then tells you another thing, trying to say whatever people want to hear.
I once knew a woman who would talk so bad behind other's backs but then act all friendly and loving toward them when they were around.
I know young people that talk all sweet and innocent around their parents but then talk completely different away from home with their friends.
I know some people that get all dressed up and come to church and talk holy while there, but then during the week you wouldn't even know they go to church by their speech.
The Book of James talks about our tongue. Specifically how much trouble it causes if not carefully guarded.
(The tongue,) With it we bless our Lord and Father, and with it we curse men, who have been made in the likeness of God; from the same mouth come both blessing and cursing. My brethren, these things ought not to be this way. (James 3:9, 10 NASB)
God is not pleased with this behavior. Don't say what people "want" to hear, tell them what they "need" to hear. Tell them about the love and mercy of Jesus.