Hypocrite
is a name originally given to an actor in a Greek play who wore a mask and thereby pretended to be someone/something which he is not. Over time, the term was used in common speech to refer to someone who looks one way on the outside while being completely different on the inside. 1
2 “Thus, when you give to the needy, sound no trumpet before you, as the hypocrites do in the synagogues and in the streets, that they may be praised by others. Truly, I say to you, they have received their reward.