The word "hypocrite" has its source from the Greek word ὑποκρίτης (hypokrites), "actor, pretender." One dictionary defines "hypocrite" as someone feigning high character; that is, someone who pretends to have admirable principles, beliefs, or feelings but behaves otherwise. The symbol for modern theater pictures two masks, one frowning, and the other smiling. The origin of the symbol is said to be from the ancient Greek theater, where actors played characters by placing masks over their faces.
The word "hypocrites" appears three times in the Old Testament. Job speaks of the "congregation of hypocrites" being made desolate, with fire consuming their "tabernacles of bribery" (Job 15:34). Elihu, one of Job's "friends" says, "But the hypocrites in heart heap up wrath..." (Job 36:13). It is interesting that both Job and his accuser use the term and declare its unpleasant reward (fire and wrath). Isaiah speaks of "the sinners in Zion," calling them hypocrites who fear the certain fire that awaits their treachery (Isa. 33:14).
"Hypocrites" is a term used seventeen times in the New Testament and all come from the mouth of Jesus. Matthew records fourteen of them, two which are repeated in the other Synoptic Gospels. In Mark 7:6 and Matthew 15:7-8. Jesus criticizes those who pretend to honor God but do not love Him. In Luke 12:56 and Matthew 16:3, Jesus questions how the religious leaders can discern the weather from physical signs, but they cannot recognize Him by His works. There is one use of the term that is unique to Luke (11:44), where He calls the Scribes and Pharisees open graves into which the unsuspecting fall. This reminds me of the cults, which present a "safe path," but are traps leading to hell.
In those verses unique to Matthew's Gospel, Jesus calls hypocrites those people who make a show of giving alms to look spiritual (6:2); those who pray for all to hear and see (6:5); those who fast for attention (6:16); those who tried to tempt Him to sin in order to trap Him (22:18); those who steal from widows and who make long prayers (23:14); those who search to find converts to their hypocritical ways (23:15); those who are dogmatically strict about the law but fail to practice it (23:23); those who "clean up" for the public, but who remain sinners inwardly (23:25, 27); those who show great respect for the tombs of the righteous and speak against those who killed them, and yet they will do the very same thing (23:29-36); and finally, Jesus proclaimed that those who mistreat their brethren will suffer the same end as will the hypocrites: weeping and gnashing of teeth (24:48-51).
To sum it up, a hypocrite is a person who pretends to love the Lord, but in actuality, hates Him. I believe it is impossible for a born-again child of God to be a hypocrite (1 Jn. 4:19). When we sin, we grieve because we have hurt God (Eph. 4:30), while hypocrites are inwardly joyful when they "put one over on the public."