Hypocrisy
Many heretical churches and groups sound very Christian as they tell you that they believe in God, Jesus Christ, and the Holy Spirit. But upon further investigation, you often find that they add additional requirements for salvation, as well as additional rules, regulations, and traditions on how you are supposed to follow God, such as membership and favoritism in their special church, and obedience to certain Old Testament laws, like tithing and Sabbath.
Here is a clear example from the Bible of the apostle Paul, who openly had to confront the apostle Pe-ter, who was hypocritically leading Gentile Christians astray by making them follow Jewish traditions.
“When I saw that they were not following the truth of the gospel message, I said to Peter in front of all the others, “Since you, a Jew by birth, have discarded the Jewish laws and are living like a Gentile, why are you now trying to make these Gentiles follow the Jewish traditions?” Galatians 2:14 NLT
It was out of fear of what others might say of him that Peter acted hypocritically by stopping eating [...]